Tomatillo

What’s still green: Arborvitae, juniper and other evergreens, roses, cholla, prickly pear, yuccas, red hot poker, grape hyacinth, hollyhock, winecup, oriental poppy, St. John’s wort, vinca, white sweet clover, alfalfa, catmint, beardtongue, snapdragon, Jupiter’s beard, coral bells, rock rose, sea pink, columbine, yellow evening primrose, perky Sue, Shasta daisy, tansy, coreopsis, cheat grass, bases of needle and June grasses; most trees have shed their leaves.

What’s red or turning red: Young apricot stems, pink evening primrose.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, yellow alyssum, winterfat, Silver King artemisia.

What’s yellow or turning yellow: Bouncing Bess, flax.

What’s blooming inside: Aptenia and asparagus fern; Christmas cactus has buds; .rochea and Christmas cactus leaves tinged with red.

Animal sightings: No sane animal is out these days.

Weather: Temperatures in low teens Tuesday morning; this is as cold as it usually gets when there’s snow on the ground in December; the only insulation now is fallen leaves; rain before midnight last night; 9:02 hours of daylight today.

Weekly update: Tomatillos were grown in the valley of Tehuacán where Richard MacNeish found the first evidence of domesticated corn long before Columbus. They still grow wild in cultivated fields in the highlands of México and Guatemala, especially in areas where ash from burned stubble promotes germination. When I saw seeds for sale, I thought they might be fun to try.

I didn’t realize they were Physalis until they began to take over the garden. None of the seed packages provided a Latin name.

I planted some five-for-a-dollar seeds in the north facing garden in 1996, and they persisted until 2001. I planted more along the eastern retaining wall in 1999, which became so thick, I began pulling them out in 2004. Unfortunately, when they break ground in spring, they look like bouncing Bess and I decimated that colony, without affecting the tomatillos.

I’d grown Physalis alkekengi in Michigan for the orange-colored Chinese lanterns that enclose the fruit, and put it on my never again list. What Hortus discretely described as "long creeping, underground stems" were their most distinctive feature. The seed cases don’t turn color until the fruit is ripe, and these relatives of the tomato have a long maturation period. I rarely saw the seed cases until late in the year, but I saw the leaves and stems everywhere.

My tomatillos have whitish roots that spread underground, while the yellow flowers look like those of tomatoes. The sepals at the top of the down facing flowers extend over the ovaries to produce the lanterns. When they began to turn papery, I wondered when they were ripe enough to pick. Since members of the nightshade family, including some non-hybrid tomatoes, are allergenic, I was cautious about popping one in my mouth.

I asked women who had migrated from México if they knew anything about tomatillos, but they looked as me blankly. I certainly had enough to give away, but could find no takers.

I finally went to the local grocer that caters to people who speak Spanish to see if it carried them, and discovered the ones it imports from México don’t look anything like what I have. Their fruits are the color of unripe tomatoes and resemble golf balls that completely fill their green cases. My fruits are golden olive grapes that hang suspended inside their tan shells.

The real Mexican tomatillos are Physalis ixocarpo. The only seed package I saved that shows the annual is one Burpee marketed to Spanish-speakers in 2000 "para salsa."

The plants I have are probably husk tomatoes. The picture on the Ferry Morse seeds that colonized shows golden yellow fruits and an ecru lantern. The photograph of Lake Valley ones that didn’t germinate is more deceptive. It shows green cases and fruits, but the fruits are small like mine. The first was promoted as "excellent for Mexican salsa" and the other described as "essential for salsas."

There’s nothing actually wrong with Physalis pubescens, except their tendency to colonize. The plants are found throughout north and south America, while tomatillos are believed to have originated in central México. The fruits, which have a sweeter taste than the acidic tomatillos, have been made into pies and jams by Americans from German and British areas. When tomatillos were adopted by Spanish colonists, they made sauces.

Fortunately, husk tomatoes are more easily tamed than the Chinese lanterns. Now I wait until the bouncing Bess is clearly identifiable before pulling most of the volunteers from the irrigated garden, and let them grow where they will in the drip line with the hairy golden asters and hybrid roses. They can hardly overwhelm either, and one of these days I may dare test their edibility.

Notes:
Bailey, Liberty Hyde and Ethel Zoe Bailey. Hortus, 1934.

MacNeish, Richard Stockton. Tehuacan Archaeological-Botanical Project, Annual Report, 1961.

United Nations. Food and Agriculture Organization. Neglected Crops: 1492 from a Different Perspective. Edited by J.E. Hernández Bermejo and J. León, 1994.

Photograph: Tomatillo (top), as sold locally, and husk tomato with manually broken shell, 28 November 2009.

Trees

What’s still green: Arborvitae, juniper and other evergreens, roses, cholla, prickly pear, yuccas, red hot poker, grape hyacinth, west-facing iris, hollyhock, winecup, oriental poppy, St. John’s wort, vinca, baptista, white sweet clover, catmint, beardtongue, snapdragon, Jupiter’s beard, coral bells, rock rose, sea pink, columbine, yellow evening primrose, perky Sue, Shasta daisy, tansy, coreopsis, Mexican hat, cheat grass, bases of needle and June grasses; number of large trees still have canopies of dead leaves.

What’s red or turning red: Young apricot stem, raspberry, pink evening primrose.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, yellow alyssum, winterfat, Silver King artemisia.

What’s yellow or turning yellow: Globe willows, apples, bouncing Bess, flax, purple ice plant.

What’s blooming inside: Aptenia and asparagus fern blooming; rochea and Christmas cactus leaves tinged with red.

Animal sightings: Rabbit hiding under car Wednesday morning; thin gray-green birds on utility line.

Weather: Cold mornings, clear starry nights, reddish new moon Thursday; last rain/attempted snow 11/15/2009; 9:05 hours of daylight today.

Weekly update: Nature never reaches an equilibrium. Something is always disrupting the balance with its demands.

Tree roots grow beyond the ability of leaves to feed them, and send messages up for more leaves. Leaves multiply beyond the ability of roots to supply them, and send help messages down. Someone cuts off parts of a tree, and new suckers emerge from hidden buds in the bark to sustain the roots.

In more temperate climates, topped trees survive on carbohydrates stored in their roots, which allow them to send out emergency branches within four to six weeks. The finer roots are sacrificed, but once some leaves are recreated, the roots return to accumulating starch in about twelve weeks. Depending on its original size, a tree can regain its original mass within a few years, although the new growth may be less securely attached to the trunk and more prone to storm damage.

Here, where dry air sucks water from the soil, trees reverse the normal process: fewer leaves mean roots’ reserves can’t be replenished. When the number of roots decreases, the branches disappear until the tree itself becomes a shadow of itself, a barely functioning trunk.

This year’s unexpected early summer rains disrupted the stasis of topped trees: roots could expand, and suddenly seemingly dead trees shot out new growth.

Down the road, someone lived under the threat of two dying cottonwoods, one directly under a utility line, one a few feet away. At some time, the tops had been removed, and the trunks had shed their bark. If there were any leaves, I never saw them from my car window.

This June they cut them to the ground, and converted the nearby garage into living space. Before they could fill the yard with a heap of foot-long slices from the trunks, new growth sprouted. By fall, the two trunks looked like shrubs.

In the village, a trailer sits behind a row of cottonwoods. Sometime in the past, one of the trees apparently died and was cut to the ground. It had sent up a new trunk that was twisted, with suckers coming from the joints in gnarled boles. When the leaves started dropping this fall, it became obvious new branches had grown from the stump this summer.

Such new growth is common for many trees, but mature cottonwoods are not known for suckering. Fires and grazing buffalo controlled their population on the prairies, and in many areas they only increased after the herds were gone.

In New Mexico, Rio Grande cottonwoods have been disappearing with artificial changes in the rivers that have reduced the amount of available water. Sprouts only survive in places where the water table is high. This summer’s rain probably made no permanent changes to the below ground water levels, but they did leave enough near-surface water to stimulate the cottonwoods to return to more active lives.

Kim Coder says, with trees, there’s "no true balance except at death’s door." This summer’s early rains were a reprieve that took the form of a great disruption of normal patterns of nature that upended expectations by homeowners who thought it finally was safe to build near the dying cottonwoods.

Notes:
Chesney Patrick and Nelly Vasquez. "Dynamics of Non-structural Carbohydrate Reserves in Pruned Erythrina poeppigiana and Gliricidia sepium Trees," Agroforestry Systems 69:89-105:2007.

Coder, Kim D. "Crown Pruning Effects on Roots," European Congress of Arboriculture, 1997.

Taylor, Jennifer L. "Populus deltoides," 2001, in United States Forest Service, Fire Effects Information System, available on-line.

Wier, Stuart K. "The Plains Cottonwood of the Southern Rocky Mountains," 1998, available on-line.

Photograph: Cottonwood stump in th village, with regrown trunk in back and new growth waving in the wind at right, 15 November 2009.

Winecup

What’s green: Trees have resumed the color changes preparatory to dropping their leaves; grape hyacinth leaves have broken through.

What’s turned/turning yellow: Cottonwoods, weeping and globe willows, sour cherries, apples, peach, Apache plume, tea roses, iris, Rumanian sage, bouncing Bess, phlox, flax, yellow alyssum, purple ice plant, Mexican hat, June grass.

What’s turned/turning red: Bradford pear, choke cherry, pasture rose, spirea, raspberry, winterfat, tansy.

What’s blooming inside: Aptenia and asparagus fern blooming; rochea and Christmas cactus leaves tinged with red.

Animal sightings: Flock of black chickens down the road, dead racoon by the village road.

Weather: Rain Friday and early this morning; 9:19 hours of daylight today.

Weekly update: This summer with its oddly timed rainfall was a boon to the early blooming members of the Mallow family, but less kind to the late summer ones.

The many stalks of hollyhocks bloomed together, and the most favored continued growing with spaced out flowers until they towered overhead. Underfoot, the deeply incised leaves on winecup runners spread everywhere in early summer, but had few flowers in August.

The roses of Sharon and sidalceas were slower to grow or bloom. While I could never say they were a disappointment, I also never had one of those moments when I was suddenly struck by their great beauty.

The roses of Sharon were the first to drop their leaves with the first frost of early October. The leaves of the sidalcea have just turned brown, while some winecup and hollyhock leaves are yellowing. The last will persist through the winter while the poppy mallow will slowly disappear.

While the roses of Sharon are threatened by late frosts every spring, the winecups are impervious to all but the coldest weather. Each spring, usually in late March, new growth begins rising from taproots, and by the monsoons the hairy stems cover the barren, dry area where I planted three seedlings in 1997.

The wine-colored poppy mallows begin blooming sometime between May 14 and May 20, then continue until frost. The five petals open from their white bases each morning and close for the night, and stay shut once pollenation is complete. The petals fall away, leaving the supporting calyx that dries brown. A beaked seedcase remains.

When a stem happened to drop into the ditch that borders the winecup bed and carries water away from the house, it spread rapidly. While the perennial reproduces by seed, the only new plants in my yard have been in that ditch as water carried the seeds towards the main garden, which they promptly invaded. The past two years the runners have been putting down roots in the pinks and snows-in-summer where they are almost impossible to remove without destroying their more desirable neighbors.

Callirhoe involucrate is less vigorous in its native tall grass prairie habitat, where it’s kept to the dry margins, either by fungus, grazing, fire or competition, and tends to brown out in late summer. When the Nature Conservancy let an old pasture go fallow with little grazing in southern Nebraska in the 1970's, the winecups increased but remained insignificant except on the silty lowland where they expanded to 2% of the vegetation in 17 years.

Researchers in Farmington tested some ninety xeric plants to determine their actual water requirements. Winecups started to fail when the moisture fell below half the usual irrigation scheme. The only places the plant grows naturally in the state are the far northeast and the San Juan valley home of that New Mexico State branch.

When freed of its natural limits, especially in a monsoon climate, winecups expand. The Flora of the Great Plains said is "adventive in waste places" and the Flora of New Mexico described it as a "common weed in gardens and cultivated ground." Even the people who sold me my plants suggest it "will slowly spread if you let it."

Next year could be especially difficult, since it’s probably spreading underground right now under all the plants that had a tougher time this year during the drier late summer. The flowers may have been killed by the late October snow, but the plants are still very much alive. Winecups are adapted to challenging weather.

Notes:
Nagel, Harold G. "Vegetative Changes During 17 Years of Succession on Willa Cather Prairie in Nebraska," North American Prairie Conference, Proceedings 14:25-30:1995.

Santa Fe Greenhouse and High Country Gardens, catalog, available on-line.

Smeal, Daniel, M. M. West, M. K. O’Neill, and R. N. Arnold. "A Differentially-Irrigated, Xeric Plant Demonstration Garden in Northwestern New Mexico," International Irrigation Show and Technical Conference, 2007.

Wooton, Elmer O. and Paul C. Standley. Flora of New Mexico, 1915, reprinted by J. Cramer, 1972.

Thompson, Jean Colette and William T. Barker. "Malvaceae Juss, the Mallow Family," including "Callirhoe involucrate" in Great Plains Flora Association, Flora of the Great Plains, 1986.

Photograph: Winecup arrested by cold with shriveled flower, dried calyxes and yellowing leaves; unaffected green leaves in back, 8 November 2009.

Bermuda Grass

What’s still blooming: Nothing.

What’s turned/turning red: Bradford pear, choke cherry, pasture rose, spirea, raspberry.

What’s turned/turning yellow: Sour cherries, apples, peach, rugosa rose, Apache plume, iris, Rumanian sage, yellow alyssum.

What’s happening inside: African aptenia and asparagus fern blooming; red tinges rochea and Christmas cactus leaves.

Animal sightings: Mice and birds testing the house’s defenses.

Weather: End of the week morning temperatures below freezing; last rain 10/28/09; 9:35 hours of daylight today.

Weekly update: When I was a child in Michigan, our winter yard was either green or white. When snow was pushed into great piles in parking lots, it turned black. Green, white and soot were the colors of winter.

When I moved to west Texas in 1982, it was late summer and the lawn was green. When temperatures fell in fall, everything turned brown, and stayed brown. Bermuda grass was grown around Abilene because it was as close as people could come to the lawns of the north in summer. However, it begins to discolor when average temperatures fall below 50 degrees and the above ground growth dies when they fall below 30. The color of winter there was papery brown.

Here bunch grasses dominate the prairie. The tops turned brown long ago, but there’s a ring of green at the bases of the clumps. The color of winter is a velvety brown.

Recently, people who live along ditches that once served hay fields have been using flood irrigation for lawns. Most have planted some grass species that’s still green, but some yards have turned tan and will remain so until late spring.

I live up hill from the old ditch that watered livestock. Most of my land is either bunch grass or scrub. However, on the east side of the house there’s some Bermuda grass that may have come in the siding when the house was moved from Texas.

It doesn’t do particularly well here. Bermuda grass likes at least 25" of water a year. In Texas, the surviving deep roots and shallow rhizomes first sent up new shoots in spring, then sent out horizontal stems to colonize new areas. Since the grass was already thickly spaced and mowed often, the vertical growth dominates and the stolons had little opportunity to survive.

Here, the plant allocates more energy to sending out stolons to find moisture than in sending up dense, long blades. There’s only one clump, between a hose and the retaining wall, that’s ever put out radiating seed spikes.

Usually when the exploring growth, with its curling tufts, ever gets near water, it also gets near other plants, which prevent it from thriving in their shade. The horizontal stems are most visible trying to cross the block walk to escape the fence and sunflowers or going over the retaining walls to get beyond the planted buffalo and blue grama grasses.

A nomad’s ability to adapt has been built into the plant’s DNA. The Cynodon genus apparently evolved in east or southeastern Africa where two species are found in the eastern tropics, one in the rift valley, one from Madagascar east, one from Transvaal to the Cape, and two elsewhere in South Africa.

The common Bermuda grass species, dactylon, is a genetic mutation with twice the number of chromosomes that spread out of Africa where it evolved into subspecies. The variety that spread through the Seleucid Empire from modern Pakistan to Turkey, and into Europe is dactylon dactylon and probably resulted from a cross between African and an Afghan subspecies.

No one knows how it got to the New World, only that it was in the colonial south before the Revolution. It may have moved first to the Carribean on some Portuguese or Dutch ship that also plied the east, then migrated from there to the south on any number of vessels that sailed between Caribbean and southern ports.

In warmer climates it stays green all year, and is used to feed cattle everywhere. Ethnologists have reported parts have been used for traditional medical cures in India, Turkey, and northwestern Iran. In this country it’s most commonly used for golf courses.

In the colder latitudes, it can still form sods. It may brown in winter, but it keeps the summers green by preventing barren soils stripped of their native bunch grasses from blowing away.

Notes:
Assefa, S., C. M. Taliaferro, M. P. Anderson, D. G. de los Reyes, R. M. Edwards. "Diversity among Cyondon Accessions and Taxa Based on DNA Amplification Finerprinting," Genome 42:465-474:1999; origin chart based on J. M. J. de Wet and J. R. Harlan, "Biosystemics of Cyondon L. C. Rich (Gramminae)," Taxon 19:565-569:1970 and J. R. Harlan., J. M. J. de Wet, K. M. Rawal, M. R. Felder, and W. L. Richardson,"Cytogenetic Studies in Cynodon L. C. Rich. (Gramineae)," Crop Science 10:288-291:1970.

Harlan, J. R., J. M. J. de Wet and K. M. Rawal "Origin and Distribution of the Seleucidus Race of Cynodon dactylon (L.) Pers. var.dactylon (Gramineae)," Euphytica 19:465-469:1970.

Newman, Dara. "Cynodon dactylon," Nature Conservatory Stewardship abstract, 1 March 1992.

Photograph: Bermuda grass stolons growing over the timber retaining wall, 1 November 2009.

Goldenrod

What’s still blooming: Chrysanthemums still have color from a distance, but up close many of the petals are stained brown.

Inside: African aptenia and asparagus fern.

What’s turned/turning red: Bradford pear, pasture rose, spirea, raspberry.

What’s turned/turning yellow: Most of the area yellow tree leaves turned brown; sour cherries, peach, rugosa rose, Apache plume, some iris leaves, Rumanian sage, catmint, yellow alyssum, Silver King artemisia.

Animal sightings: Mice have been trying to move into the house.

Weather: First snow landed on frozen rain on low leaves and stems in Monday morning dark; rain early Wednesday, then snow late; Tuesday morning in the high 20's, Thursday down to low 20's, and Friday.in mid 20's with raw wind; yesterday weather back to normal sunny 30 degree temperature swing; 10:01 hours of daylight today.

Weekly update: There are things I know, objectively, to be true, but have never experienced.

I know horseweed has tiny white flowers, although I’ve never seen one. I see buds and I see seed heads, but I never see the petals opened. The closest I’ve come was a dull day with clouds hiding a bright sun. In the special half light that extended into afternoon, I saw some flowers partly opened, almost daisies.

It’s often at such special times, like All Hallows’ eve, when conditions aren’t quite normal, that the usually invisible is revealed.

I know goldenrod is a member of the composite family, but all I’ve ever seen were yellow knobs on curving stems, usually from a distance. In Michigan in the 1970's, the rhizomes grew in large stands with white yarrow on land abandoned when I-94 was built in the early 1960's. This summer one large and at least three small patches rose from sides of irrigation ditches along the village periphery.

This year’s rain patterns were unusual. Showers continued into July, when it’s usually dry. Then, there was no rain in the usual monsoon season. There was more water than usual part of the summer, and little the other part. Few sunflowers or purple asters bloomed. We had no fall. It wasn’t their world.

My goldenrod, however, had larger flowers than usual and I could actually see the golden rays ringing flattened domes. Now the heads look like thistles. The white awns anchored to seeds are visible within the prongs of receptacle bracts that remain when the fluff has flown, like cotton bolls before the gin removes the debris.

Two weeks ago, the white balls reflected light. A week ago, after two days of rain and two days of cold, the pappus hairs that had once surrounded the florets were more dispirited, the browns more prominent. Yesterday, after more rain, more cold, and even some snow, the receptacles still clutched their remaining winged achenes.

One reason I could see my flowers so clearly this summer is they are stiff goldenrod plants I bought from Wisconsin’s Prairie Nursery in 2005. The major difference between Solidago rigida and the more common canadensis is that, while they have similar numbers of ray petals (6-13 versus 8-14), my species has 14 to 35 disc florets rather than the 3 to 6 found on the common perennial.

The sheer need for space for the disc flowers pushes the petals apart, making the center more visible. The fact the rigida disc corollas are also two to three times the size of canadensis only emphasizes the difference.

Some taxonomists have argued large flowers like mine aren’t really goldenrods and should be moved to another genus, tentatively called Oligoneuron. However, geneticists found rigida not only shares the same DNA with canadensis, but its subtribe appears to be an older, more basal member of the group.

Apparently, goldenrod began like any other composite, a daisy in a large cluster, somewhere east of the Mississippi. As conditions changed, the flowers shrank, but nature compensated by creating more to produce the same reproductive effort. However, rather than create great clusters like yarrow or horseweed to accommodate the increased number of florets, nature created the classic goldenrod form by extending the stem into a gooseneck and spreading the flowers along one edge.

Today, the USDA website has distribution maps for 75 Solidago species. Many are limited to the areas where they evolved. Of those that did spread, most live either east of the great plains, like stiff goldenrod, or in the west. Common goldenrod is the only one that has adapted almost everywhere. It can’t handle the humid southeast and, early in the twentieth century, Elmer Wooton and Paul Standley suggested in New Mexico, it only grew in Chama and on "moist ground in the upper Sonoran" that includes the Rio Grande valley.

This summer even the local goldenrod expanded with the unexpected early moisture. The peduncle stems, that hold individual flowers, grew longer, so the wands became airy plumes. Last weekend those canadensis heads, by then turned white, still maintained their form. But one, growing along a curve where its pappus of white fluff caught the morning light proudly proclaimed to any passing driver, "See I am a composite, see my glorious crown."

Notes:
Nesom, G. L. "Taxonomic Infrastructure of Solidago and Oligoneuron (Asteraceae: Astereae) and Observations on Their Phylogenetic Position," Phytologia 75:1-44:1993.

Semple, John C. and Rachel E. Cook Entries on Solidago, S. canadensis, and S. rigida at efloras Flora of North America website.

US Department of Agriculture plant profile for Solidago, available on-line.

Wooton, Elmer O. and Paul C. Standley. Flora of New Mexico, 1915, reprinted by J. Cramer, 1972.

Photograph: Stiff goldenrod seed head, 25 October 2009, winterfat in back.

Pampas Grass

What’s still blooming somewhere: Tea roses, red hot poker, winecup, scarlet flax, drab chamisa, chocolate flower, chrysanthemum, Mexican hat, áñil del muerto, tahokia daisy, blanket flower, hairy golden and Mönch asters; yellow leaves and fallen apples litter the ground, grapes shriveling into raisins.

Inside: African aptenia and asparagus fern.

What’s turned/turning red: Lapins cherry, Bradford pear, pasture rose, spirea, raspberry, sand cherry, Virginia creeper, leadwort.

What’s turned/turning yellow: Cottonwood, globe and weeping willows, Siberian elm, tamarix, beauty bush, sour cherries, peach, rugosa rose, Apache plume, lilacs, hosta, Rumanian sage, catmint, yellow alyssum, Silver King artemisia, purple coneflower.

Animal sightings: Rabbit, large black harvester and small dark ants.

Weather: Rain Tuesday and Wednesday, followed by mornings so cold frost lay on lawn grasses and water froze in the village arroyo; 10:18 hours of daylight today.

Weekly update: There are times when I drive by someone’s yard and see something so beautiful, I wonder "how’d they do that."

Near the village someone has two magnificent clumps of pampas grass at the end of her driveway that have thrown up white plumes that wave 6' high against a backdrop of yellowed trees.

It may sound quite ordinary, except Cortaderia selloana is a zone 8 plant that can survive in zone 7 Albuquerque in favorable situations. There are some shorter cultivars like Pumila which tolerate zone 6 Santa Fe. But, Española is zone 5. The average low temperature for zone 8 is twenty degrees and, even in our mildest winters, there are mornings in the high teens.

Many western gardeners have learned the USDA system of zones is more reliable in the east than on the plains and in the Rockies. The idea of using a single variable, mean low temperature, to predict that ability of plants to survive was introduced in 1927 by Alfred Rehder, who was interested in describing the vegetation belts he saw across the country and the Appalachians.

According to Peter Del Tredici, Donald Wyman redefined Rehder’s concept to use the average minimum temperature in 1938 when he was at the Arnold Arboretum. He and other specialists continued to issue competing modifications until the USDA published the standard developed by Henry Skinner in 1960 at the National Arboretum. The agriculture department has since issued several revisions, and other groups, like Sunset magazine, continue to publish alternative guides for this part of the country.

But no matter how sensitive the tool, nothing will explain how those thriving South American plants have survived at least one winter.

The owner has done everything she could to create a favorable environment. The land around her house is surrounded by high, stone walls, that also line both sides of the sealed drive. In the winter the dark walls and paving absorb daylight, then radiate heat as they cool in the night. The surrounding microclimate is warmer than the prairie.

The owner has also been helped by her location. She lives about three-quarters of a mile from the river and about five hundred feet from a wide arroyo. A concrete-lined irrigation ditch passes near the outer wall carrying water in summer. Trees across the road help deflect the drying
winds of February.

Her natural and manmade location helps, but still can’t explain what makes her rhizomes so successful. My friend from Uruguay tells me what he calls horses’ tails grows on the sandy beaches of the eastern shore where the coldest it gets in winter is a few degrees below freezing. Tour groups advise it can be seen in its native habitat in the Costanera Sur nature reserve in Buenos Aires on the Rio de la Plata.

It also grows to the southwest at the Ernesto Tornquist Provincial Park with the 3,700' Cerro de la Ventana about 75 miles inland from the Atlantic. There, Natalia Cozzani and Sergio Zalba have found birds nesting in the tussocks of dried grass that accumulate beneath the fountains of sharp-edged foliage.

Pampas grass prefers moist winters and dry summers, but is not restricted to the coast. The perennial is also found in Brazil, Paraguay and Chile. Texas A&M has published a photograph of white heads growing like dense scrub in western Mendoza province in what looks like a tree-lined mountain meadow backed by snow-streaked peaks.

The wild species, which can reach 20', is probably not the one available in trade: nursery catalogs advertize 10' heights. Many are probably sterile cultivars that don’t shed the pollen, flowers and seeds my friend says fill the Uruguayan air. My neighbor probably has a hardier cultivar, but it’s still unique in this area for its height, width and vitality, a wonder to behold.

Notes:
Cozzani, Natalia and Sergio M. Zalba. "Estructura de la Vegetación y Selección de Hábitats Reproductivos en Aves del Pastizal Pampeano," Ecologáía Austral 19:35-44:2009.

Del Tredici, Peter. "The New USDA Plant Hardiness Zone Map," Arnoldia 50:16-20:1990.
Rehder, Alfred. Manual of Cultivated Trees and Shrubs, 1927.

Texas A&M University Herbarium. Vascular Plant Image Library photograph of Cortaderia selloana taken by Hugh Wilson.

Photograph: Pampas grass in the wind, 17 October 2009.

Blackberry Lily

What’s still blooming somewhere: Tea roses, California poppy, red hot poker, winecup, chamisa, chocolate flower, chrysanthemum, Mexican hat, áñil del muerto, broom senecio,
tahokia daisies, Maximilian sunflowers, purple and hairy golden asters, untouched blanket flower buds, low growing Mönch asters.

Bedding plants: Moss rose.

Inside: African aptenia and asparagus fern.

What’s turned/turning red: Pasture rose, spirea, raspberry, sand cherry, skunk bush, leadwort, pink evening primrose, Virginia creeper.

What’s turned/turning yellow: Cottonwood, globe and weeping willows, black locust, Siberian pea, Siberian elm, tamarix, beauty bush, cherries, peach, rugosa rose, lilacs, lilies, hosta, ladybells.

Animal sightings: Large black harvester and small dark ants

Weather: Tuesday’s morning’s rain followed by great squawking of birds towards the river when I was leaving for work; 10:38 hours of daylight today.

Weekly update: When Americans and the Chinese look at the same thing, say a blackberry lily, they don’t see the same thing.

When Thomas Jefferson planted what he knew as Ixia chinensis in 1807, he was probably interested in the loose clusters of six, spotted, orange petals that open late morning. Soon other flowers from other parts of the world surpassed their beauty, and the iris-shaped leaves persisted on their own in ditches, along roads, and in fields east of the Rockies.

Today, gardeners are told to grow the shorter, less garish Freckle Face cultivar for its fall and winter interest. Around September 26, the pear-shaped pods on my plants split open to reveal rows of shiny black seeds. The reflexed outer wraps have since dried a papery white.

When the Chinese look at shegan they see medicine.

Steven Foster and Yue Chongxi interpret Shi Zhen Li as having recommended it for throat cancer in 1578. When George Stuart translated Li’s work in 1911, he simply said it had "some special popularity in diseases of the throat" and reported it was used for breast cancer.

Chinese and scientists from other countries that still have some respect for traditional plant medicine have been combing reports of traditional practices looking for potentially useful plants. In the 1970's, doctors at the Chinese Academy of Medical Sciences were testing the folk methods for treating bronchitis.

By the 1990's, chemists were isolating more than a dozen compounds from the rhizomes of Belamcanda chinensis, and identifying some as flavonoids. In 2000, Li Xin Zhou and Mao Lin had been able to create a synthetic form of one, and demonstrate its effectiveness against inflamation. Lin and others later showed the compound was a powerful antioxidant, and it has since attracted a great deal of interest.

Most recently, Asian scientists have been doing the necessary work to make possible the mass production of the blackberry lily compounds. They have been creating tests for the cost-efficient evaluation of extracts, verifying that cultivated plants don’t differ in efficacy from the ones used in laboratory tests, and trying to develop synthetic forms.

Meantime, European scientists associated with a German herbal medicine company, Bionorica, have identified two of the flavonoids, irigenin and tectorigenin, as phytoestrogens that could be used to counter problems caused by sex hormones, especially prostrate cancer. They took out their first patent on a blackberry lily extract in 2002.

Most Americans never look at the roots that so interest the Chinese. Gardeners can buy plants grown from seed supplied by Jelitto, and are told to let the short-lived perennials perpetuate themselves by going to seed. They wouldn’t know the dried roots are chrome yellow inside and have an acid taste when fresh.

The Chinese aren’t particularly interested in the inedible seeds. In the nineties, some Japanese chemists identified four enediones in the seeds, but none have stimulated any further research.

American’s don’t just not see the blackberry lily’s roots. They’ve been told it’s a member of the iris family and therefore should be avoided as potentially toxic. Chinese don’t just ignore the seeds. They’ve been warned that only the roots are useful and not to substitute aerial parts in their formulas. We both see what we’ve been told to see.

Notes:
Bionorica AG, Wolfgang Wuttke, Hubertus Jarry, Michael A. Popp, Volker Christoffel, and Barbara Spengler. "Use of Extracts and Preparations from Iris Plants and Tectorigenin as Medicaments," patent 2002/092111, 21 November 2002.

Chang, Tzu-Ching, Chih-Liang Wang, and Hsiu-Lan Wang. "Pathogenetic and Clinical Study of Bronchiolitis," Chung-Hua I-Hsueh Tsa-Chih 12:731-73:1976.

Foster, Steven and Yue Chongxi. Herbal Emissaries: Bringing Chinese Herbs to the West: A Guide to Gardening, Herbal Wisdom, and Well-being, 1992.

Li, Shi Zhen. Ben Cao or Pen Ts'ao, 1578.

Morrissey, Colm, Jasmin Bektic, Barbara Spengler, David Galvin, Volker Christoffel, Helmut Klocker, John M. Fitzpatrick, R. William and G. Watson. "Phytoestrogens Derived from Belamcanda chinensis Have an Antiproliferative Effect on Prostate Cancer Cells in Vitro," The Journal of Urology 172:2426-2433:2004.

Seki, Katsura, Kazuo Haga and Ryohei Kaneko "Belamcandones A-D, dioxotetrahydrodibenzofurans from Belamcanda chinensis," Phytochemistry 38:703-709:1995.

Stuart, George Arthur. Chinese Materia Medica, 1911, reprinted by Gordon Press, 1977.

Wang, Qing Li, Mao Lin and Geng Tao Liu. "Antioxidative Activity of Natural Isorhapontigenin," The Japanese Journal of Pharmacology 87:61-66:2001.

Zhou, Lin Xin and Mao Lin. "Studies on the Preparation of Bioactive Oligomerstilbene by Oxidative Coupling Reaction (1)-Preparation of Shegansu B using Silver Oxide as Oxidant," Chinese Chemical Letters 11:515-516:2000.

Photograph: Blackberry lily seeds, 11 October 2009.

Broom Senecio

What’s blooming in the area: Tea roses, chamisa, áñil del muerto, broom senecio, tahokia daisies, Maximilian and native sunflowers, purple, and hairy golden asters; cottonwoods beginning to yellow.

What’s blooming in my yard: California poppy, red hot poker, snapdragon, winecup, chocolate flower, chrysanthemum, Mexican hat; leaves turning yellow on globe willow, black locust, Siberian pea, lilacs, lilies, hosta, ladybells; turning red on pasture rose, spirea; blown off roses of Sharon.

Bedding plants: Moss rose.

Inside: African aptenia and asparagus fern.

Animal sightings: Rabbit, wasp, grasshopper, large black harvester and small dark ants; large black fowl in odd places along the main road when I was leaving for work.

Weather: Rain Wednesday, frost on my car window Friday morning, fog on the river; 11:06 hours of daylight today.

Weekly update: The first hard frost, and what red or blue flowers remain lay hidden amongst cushions of seeds. It’s time for nature’s medley of yellows.

When I drive out of Santa Fe, bands of aspens loom from the distant Sangre de Cristo. When I drop down into Pojoaque, cottonwoods pick out the watercourse. Here, mossy yellow chamisa rise above the mustard snakeweeds and golden hairy asters. Clearest of all are the broom senecios.

Last weekend they peered from under chamisa shrubs in the arroyo and swayed by themselves in the sand. A few skim great mounds along the road, while the ones that have moved about my garage have clusters of six to eight skinny petaled daisies atop sparsely leaved stalks. A seed, attached to a white, dandelion-life tuft, has come up to the south by the fence that stopped its flight and a single, bright green stalk has risen from its taproot.

Broom senecios were seen by John Frémont when he was exploring the Sweet Water in Wyoming during the first part of August in 1842. One likes to imagine, when one is told someone was the first easterner to see a plant, that his report implies something about the primeval vegetation of the area.

With this groundsel, I’m not sure what past Frémont represented. Theodore Barkley suggests the plant is encountered infrequently in western South Dakota and Nebraska, and only found occasionally westward in the Great Plains, although its known in all the plains states.

The Sweet Water is the link between the South Pass through the Rocky Mountains and the river Platte that travelers followed from Missouri. A group of Astor Fur Company men had discovered the route from the west in 1812. Jedediah Smith and Thomas Fitzpatrick rediscovered what became the Oregon Trail from the east in 1823.

Soon, fur traders were using the route to bring pelts back to Saint Louis from their annual rendezvous with trappers. In 1830 the more enterprising William Sublette built a wagon road to haul his goods, a path Benjamin Bonneville used two years later to scout the area for the federal government.

By the time Frémont arrived, the trail was well established, but not yet heavily used. The valley of the Sweet Water varies from a few yards to five miles in width. He saw absinthes when he was near the mouth, and asters near the pass. Occasionally the river was bordered by "groves of willow" and nearer the pass, by aspen, beach and willow.

During his third day in the 120-mile-long valley he noted "numerous bright-colored flowers had made the river bottom look gay as a garden." Later he contrasted the occasional side valley of "deep verdure and profusion of beautiful flowers" with the "great evaporation on the sandy soil of this elevated plain, and the saline efflorescences which whiten the ground."

About the same time, he remembered seeing "many traces of beaver on the stream; remnants of dams, near which were lying trees, which they and cut down." Probably the first environmental change that favored the composites over the more valuable grasses was the death of the beavers who may have kept all those salt plains irrigated. In the mountains beyond the pass, Frémont noted both the presence of both beavers and saturated grasses.

Soon the valley would be filled with wagons in summer. The Whitmans had followed the Sweet Water in 1836, as did the wagon train of 1841 led by John Bartleson and John Bidwell and the one led by Elijah White in 1842. Fremont himself had so many men with him they needed to kill two buffalo a day to feed themselves.

Broom senecios do well in slightly disturbed soils. The only scientists I’ve read who’ve described an area dominated by the bright green subshrubs were surveying a part of the National Guard’s Camp Navajo, outside Flagstaff, that had been burned, then used for detonation exercises. The land was desolate and, no doubt, windblown, but the soil surface was not damaged the way it would have been by wagons or flocks of sheep.

In the Chihuahuan desert, others have noticed that when the soil is seriously disturbed, the thin veneer of microorganisms that sustains the grasses is destroyed and shrubs invade. The chamisas and other Chrysothamnus species protect soil nutrients while the ground between the shrubs continues to erode.

In the arroyo, the senecios growing with chamisa are taller, near 30", and have a number of stems with more clusters with more flowers crowded into the heads. The solitary plants, like those in my yard, at most have gotten 24" tall and the starry shapes of the flowers are more distinct as they overlap one another in open lattices.

In addition to its ability to survive sand and drought, Senecio spartioides was chemically prepared to protect itself from wagon train draught animals. All its parts contain pyrrolizidine alkaloids that stop most from eating them; when animals or humans do overindulge they die from liver damage.

Nature protects itself as soon as it’s disturbed. I suspect Frémont didn’t just see climax vegetation of the Great Plains, but the first response to its destruction.

Notes:
Barkley, T. M. "Asteraceae Dunn., the Sunflower Family" in Great Plains Flora Association, Flora of the Great Plains, 1986.

Evans, R. D. and J. R. Ehleringer. "Water and Nitrogen Dynamics in an Arid Woodland," Oecologia 99:233-242:1994.

Frémont, John Charles. The Daring Adventures of Kit Carson and Frémont, 1885.

Young, Erin, Abe Springer and Ty Ferré. "Frost Penetration Depth and Frost Heave at Camp Navajo: Year 1," 29 October 2004.

Photograph: Broom senecio leaning out from under chamisa in the arroyo, 4 October 2009.

White Prairie Clover

What’s blooming in the area: Tea roses, leather leaved globemallow, white prairie clover, Crimson Rambler morning glory, goats’ head, chamisa, winterfat, ragweed, snakeweed, áñil del muerto, broom senecio, tahokia daisies, purple, heath, and hairy golden asters, pampas grass; bittersweet berries; sand burs ripening; tamarix leaves turning yellow, Russian thistle and prostrate knotweed turning red; grape and Virginia creeper leaves dead; red pepper plants dead.

What’s blooming in my yard, looking north: Mexican hat, chocolate flower, chrysanthemum; Lapins cherry leaves turning orange.

Looking east: Snapdragon, large-leaved soapwort, Maximilian sunflowers.

Looking south: Sweet pea; zinnias and cosmos dead

Looking west: Russian sage, catmint, calamintha, David phlox, Mönch aster; leadwort leaves turning burgundy; skunk bush orange red.

Bedding plants: Moss rose, sweet alyssum; tomatoes dead.

Inside: African aptenia and asparagus fern; rochea leaves turned red.

Animal sightings: Brown speckled woodpecker landed on front porch post poised to attack; rabbit, geckos, large black harvester and small dark ants, cows brought in to graze in village.

Weather: Below freezing temperatures Friday and Saturday mornings; last rain 9/24; 11:36 hours of daylight today.

Weekly update: When plants die that have been around for some years, I mourn a little, as I would for someone I knew years ago. When the plants are relatively new, I shrug and remind myself it’s hard to find perennials that can survive this environment.

When the wild prairie clover disappeared last year, I wondered if it was simply short-lived. It had only been growing under the protection of a clump of June grass at the end of my drive since 2006. I knew a gopher could have gone after the deep taproot. The rabbit as easily could have eaten the sparse, light green foliage.

When a five-year-old stand of the white flowers died at the Bridger Plant Materials Center in Montana, people were less philosophical. After all, these were the scions of the Antelope seed they had collected in Stark County in 1947 and released in 2000 to growers for prairie restoration projects. Entomologists discovered the larvae of long-horned beetles had burrowed into the root crowns.

Those who were already using the kidney-shaped seeds in their restoration projects wanted to know why they failed to germinate. The most obvious answer was that the clover is a legume that needs a specific bacteria in the soil to help its roots convert soil nitrogen to feed the plant.

Some also pointed to the seed-stealing habits of rodents, while others noted the need for cold moisture or abrasion to break the seed’s dormancy, and that irrigation increases the existence of particular rust parasites.

Timothy Dickson and William Busby found a more complicated answer: a prairie is not a uniform mix of plants. Dalea candida grows better when there is less competition from warm season grasses. I’ve noticed some time ago that in this area, the only plants that live with the bunch grasses are things like snakeweed and winterfat and then only when seeds drop where the wind has loosened the soil enough and water happens to pass.

Most of the forbs are either in the arroyo, or have sprung up where off-road vehicles have killed the grass. Of course, Russian thistle is the most likely volunteer, but other annuals and perennials do emerge. Last weekend white prairie clover was growing on the north side of the arroyo plain, near the path of the water flow, and in one of the feeders.

The herbaceous perennial can grow anywhere from the prairie provinces of Canada to Chihuahua, Durango, and Sonora below 7000'. In this country, it avoids the far west and New England, but can grow in the glades and savannahs of the southwestern south. Early in the last century, Elmer Wooton and Paul Standley found it grew on open slopes throughout New Mexico.

Dan Moerman noticed the distribution of native people utilizing two subspecies is much more limited. Outside the Pawnee and Kiowa, every group lives in or near New Mexico. Going down the Rio Grande are the Santa Clara, the San Ildefonso, and San Felipe. Moving west, he read about the Laguna, Acoma, Navajo, and Hopi. No one reported a use that suggested it was common enough to be built into the material, medicinal or nutritional culture.

If a plant is this difficult to grow, I wonder why so many try. Although some give the usual answer about forage quality, I suspect for many it’s nostalgia for lost prairies. It may indeed attract a number of bees and contain chemicals that make it easier to digest, but plants like Illinois Bundle Flower are better.

The white flowers are simply something you remember in the grass, and hate to see disappear. The small flowers open at the bases of tall, narrow columns, and the rings rise through the blooming season. The modified pea flowers have a single wide banner, but the other petals are reduced to flaps amongst the stamens. When the cone is short and flowers fill the entire head, the usual tutu of lightness turns into a fairy’s wand.

Notes:
Dickson, Timothy L. and William H. Busby. "Forb Species Establishment Increases with Decreased Grass Seeding Density and with Increased Forb Seeding Density in a Northeast Kansas, U.S.A., Experimental Prairie Restoration," Restoration Ecology 17:597-605:2009.

Moerman, Dan. Native American Ethnobotany, 1998.

Wooton, Elmer O. and Paul C. Standley. Flora of New Mexico, 1915, reprinted by J. Cramer, 1972.

Wynia, Richard. "White Prairie Clover," USDA Natural Resources Conservation Service Plant Guide, 2008.

Photograph: White prairie clover with grass on the bank of the arroyo, 27 September 2009.

Leadwort

What’s blooming in the area: Tamarix, tea roses, Apache plume, butterfly bush almost gone, trumpet creeper, Japanese honeysuckle, silver lace vine, leather leaved globemallow, alfalfa, white sweet and white prairie clovers, yellow evening primroses, datura, goats’ head, bouncing Bess, stickleaf, chamisa, winterfat, ragweed, snakeweed, native and farmer’s sunflowers, áñil del muerto, horseweed, wild lettuce, African marigolds, tahokia daisies, purple, heath, strap-leaf and hairy golden asters, pampas grass; canna buds, bittersweet berries; more Virginia creeper turning red.

What’s blooming in my yard, looking north: Zucchini, nasturtium, Mexican hat, chocolate flower, blanket flower, black-eyed Susan, chrysanthemum; leaves on butterfly weed turning yellow, catalpa leaves turning yellow and dropping, sand cherries turning red, seeds on blackberry lily.

Looking east: California poppy, hollyhock, winecup, snapdragons, Jupiter’s beard, large-leaved soapwort, Autumn Joy sedum, garlic chive, Maximilian sunflower; leaves on peony turning color.

Looking south: Rose of Sharon, sweet pea, Crimson Rambler morning glories, zinnia, cosmos; grapes turning red.

Looking west: Caryopteris, Russian sage, catmint, calamintha, David phlox, leadwort, purple ice plant, Silver King artemisia, purple coneflower, Mönch aster; leaves turning orange on skunkbush and white spurge; peach leaves turning yellow and dropping.

Bedding plants: Moss rose, sweet alyssum; edible tomatoes.

Inside: South African aptenia.

Animal sightings: Rabbit, geckos, bees, wasps, grasshoppers, large black harvester and small dark ants.

Weather: Short bursts of strong winds late some days; rain Thursday; 11:55 hours of daylight today.

Weekly update: Some flowers are definitely camera shy. Some weigh so little, they never stay still long enough for a camera to capture them. Others reflect so much light they blind the lens. The blues are trickiest of all, because their wiles defeat the camera itself, not just the photographer.

Of all the blue flowers in my garden, leadwort is the hardest to photograph. Early in the morning, when the Chinese natives are in shade, images look like they were taken underwater. By the time the sun reaches the west facing bed, the petals have begun to protect themselves by reflecting light. I was only able to get a clear picture last Sunday when the sky was still bright, but a little rain was falling. Even then the color was wrong.

Unlike the old silver-based film cameras, nothing is constant with a digital device. Then, if a picture was out of focus, the photographer knew he or she hadn’t set the distance parameter, the focal length, properly. With a computer-controlled camera, two parts of a plant the same distance from the lens, will appear in different degrees of detail. The reddish brackets that hold the pinkish tubes of the five-petaled leadwort flowers are always clear.

The same variation occurs with color. When the light is right, the leaves, the stems, the tubes and brackets are reasonably true, but not the petals. The reds, greens, browns and whites are fine. Only the blues are bad.

The chemicals in the plant absorb light both as part of photosynthesis and as the nature of matter. What we see is the light that’s not absorbed. In the case of leadwort, the flower is absorbing the yellow center of the visible light spectrum and ignoring the reds and blues, which the human eye combines into purple. On the other hand, the leaves are rejecting the green, and using the rest of the light to feed themselves

Jeffrey Harborne identified the flower pigment in Ceratostigma plumbaginoides as europinidin, a reddish blue anthocyanin derivative of the bluish purple delphinidin typically found in members of the plumbago family. Later this fall, when the leaves turn a burgundy red, the plant will have produced a cyandin monoside that will reflect light differently. Earlier, when they broke through the ground the second week of May, the new leaves were a shiny green.

Chemists themselves have troubles defining colors precisely. When William Lawrence’s team was testing the anthocyanin pigments in fall leaves, they found a number had one hue when seen in daylight and another when seen in artificial light. The nature of light is not constant from morning to noon, from clear to cloudy, from June to September.

Whenever I try to explain to myself what has happened with my pictures I get tangled in the differences between the reality of the physicist’s linear spectrum that fades into infrared at one end and to ultraviolet at the other, and the vocabulary of the artist’s color wheel which sees purple as the junction between red and blue. When I compare the photograph with the flower I see, it looks like the blue is bad because the red has been lost, only the blue has become lighter, not darker as a consequence.

I finally defined the two colors, the actual flower and its representation in the language of the computer monitor, which sees everything as a mix of red, green, and blue. The one is roughly 130 parts red to 50 parts green to 255 parts blue. The other is 100 parts red to 130 parts green to 245 parts blue. The first formula lacks the depth of the petals, but 255 is the maximum allowed for any color. The second doesn’t capture the sheen or white overtones of the photograph.

My camera uses the established technology that existed when it has introduced in 2005. The light enters through the lens to bounce against a prism that redirects it down to the CCD chip that converts the light into electronic impulses. Thom Hogan indicates such chips are more attuned to the high-energy infrared and somewhat blind to the low-energy blues. Some of the loss of blue, from 255 to 245, may be a consequence of that limitation; some of the loss of red (from 130 to 100) may come from the manufacturer’s attempt to compensate for the infrared sensitivity.

Computer chips only see on and off, which translate into black and white monochromes. The first stage of coloration comes from two layers of filters that sit above the CCD chip. One alternates red and green filters, the other blue and green so every point on the chip has one green filter and one of another color. At this point, the only loss of color comes from the quality of the filters.

The camera then takes the information from the chip and from the filters and combines them, using proprietary algorithms that try to reconstruct the relative importance of the data captured by the two layers. Since engineers know most people are more sensitive to green, than to red or blue, they tend to favor green when the pattern isn’t clear. And so, the amount of green in my picture is increased from 50 to 130, which distorts the flower color.

The variations increase when the image is transferred to a computer monitor or printer, because each piece of equipment has its own way of translating the RGB schema.

I originally asked questions about my camera’s technology so I would have some idea what features I needed if I replaced it. It never occurred to me to alter my garden so only the flowers that could be photographed would be allowed to grow. Nature is still more complex that it’s scientific representation, and flowers can be remembered without mechanical devices.

Leadwort is one of the last perennials to emerge in spring, rising in new places along the soaker hose where its rhizomatous roots have extended themselves. It’ll be one of the more colorful this fall. It’s now been putting out low flowers every few days since the middle of August. I grow it for the pleasures lived and those remembered, not for being recordable.

Notes: Charge-coupled devices (CCD’s) were developed in 1969 by Willard Boyle and George E. Smith at AT&T Bell Labs. The network of filters was patented by Bruce Bayer for Kodak in 1976. In the nineteenth century, Thomas Young and Hermann von Helmholtz established humans perceived colors from only three band widths of light; the existence of separate human receptors for red, green and blue (RGB) was finally established in 1983 by Herbert James Ambrose Dartnall, James K. Bowmaker, and John D. Mollon. What I call a part of color, using the language of artists, actually refers to the intensity of the light measured by the physicist.
Hogan, Thom. "How Digital Cameras Work," bythom website, last revised 9 April 2009, provides the clearest explanation for the layman.
Harborne, J. B. "Comparative Biochemistry of the Flavonoids-IV: Correlations Between Chemistry, Pollen Morphology and Systematics in the Family Plumbaginaceae, " Phytochemistry 6:1415-1428:1967.
Lawrence, William John Cooper, James Robert Price, Gertrude Maud Robinson, and Robert Robinson. "A Survey of Anthocyanins. V," Biochemistry 32:1661-1667:1938.
Photograph: Leadwort, taken around 3:30 on 20 September 2009.

Heath Aster

What’s blooming in the area: Tamarix, tea roses, Apache plume, butterfly bush, trumpet creeper, Japanese honeysuckle, silver lace vine, leather leaved globemallow, alfalfa, white sweet clovers, white and yellow evening primroses, datura, Heavenly Blue and ivy-leaf morning glory, scarlet creeper, bindweed, goats’ head, bouncing Bess, pale trumpet, stickleaf, clammy weed, spurge, pigweed, Russian thistle, winterfat, ragweed, snakeweed, native and farmer’s sunflowers, áñil del muerto, Hopi tea, horseweed, wild lettuce, purple, heath, strap-leaf and hairy golden asters, goldenrod, tahokia daisy; bittersweet berries, apples falling.

What’s blooming in my yard, looking north: Zucchini, nasturtium, Mexican hat almost gone, chocolate flower, blanket flower, black-eyed Susan almost gone, chrysanthemum.

Looking east: California poppy, hollyhock almost gone, winecup, snapdragons, Jupiter’s beard, large-leaved soapwort, Autumn Joy sedum darkening, garlic chive, Maximilian sunflower.

Looking south: Blaze roses, rose of Sharon, sweet pea, Crimson Rambler and reseeded morning glories, zinnia, cosmos.

Looking west: Caryopteris, Russian sage, catmint, calamintha, flax, sea lavender, David phlox, leadwort, perennial four o’clock, purple ice plant, Silver King artemisia, purple coneflower, Mönch aster.

Bedding plants: Moss rose, sweet alyssum.

Inside: South African aptenia.

Animal sightings: Rabbit, hummingbird, geckos, bees, wasps, grasshoppers, large black harvester ants, explosion of small dark ants

Weather: Rain Wednesday and Thursday; mornings were cold enough for the furnace to come on and my neighbor to fire up his chain saw to cut fire wood; 12:15 hours of daylight today.

Weekly update: Mornings turn cold, heath asters open, and my thoughts turn to Billy Grammer. In 1959 he sang "summer’s almost gone, winter’s coming on."

Grammer’s answer was it’s time to travel on. That’s good advice for hummingbirds raiding the last hollyhocks, but what about the bees and wasps and other insects still flitting about?

My bees probably come from some hive maintained down by the orchards, and will survive the winter by clustering together and beating their wings to produce enough heat to keep themselves warm. The six-legged creatures only venture out when temperatures rise above 50, so will subsist on stored honey.

Other bee species and wasps have no such surplus. The social wasps, and hornets that are part of that insect group, spent the summer feeding larvae with animal proteins from insects they had killed, including ones that would have eaten the leaves or sucked the juices from my wild asters. The adults themselves lived on sugars and got some nutrients from the process of feeding the grubs, some from flowers, and some from foraging in garbage.

Now the larvae are grown and everyone needs to eat. In some species, the young females will impregnate themselves and burrow under leaves or find an attic to hibernate for the winter. Others will simply lay eggs which remain dormant until spring. The rest, the workers, will die.

Unfortunately, they all need food just when most flowering plants are responding to nature’s signals that winter’s coming on by moving to seed production. Wasps don’t have the specialized tongues of bees and need open, shallow autumn flowers where nectar is easily available. They must have had a tough time this past week when the white asters pulled up their twelve ray flowers to shed the rain.

The small, white composites, like many related asters, seem to have two growth cycles related to changes in light. The basal rosettes emerged this year in late April, but the tall plumes of narrow green leaves didn’t appear until late July, nearly six weeks after the long days of mid-summer stimulated their production. It wasn’t until the shorter days of fall that the flower clusters were ready to open.

With so little time to produce seed and visitations by smooth wasps, who aren’t as efficient at pollinating as hairy bees, heath asters have found others way to perpetuate themselves. Every spring I remember how the skinny stalks turn into a hedge that overshadows everything before smothering the lower plants when they collapse. I pull out most of the plants, but strands of their stolonous roots break off.

After the heat of summer drives me inside, the perennials spread underground and push up new shoots back near the water and paths. By then, it’s too late to do anything except plan how to control them the next year.

Man has found little use for Aster ericoides. Some call it steel weed because the woody brown stems dull their tools; others call it good-bye meadow because it’s poor forage. Only the Meskwaki used it to their lash together their sweat lodges and tested its herbal uses.

The seeds, if they get produced, can last several years. Heath asters are one of the first things to return in tall grass prairies when fields are abandoned. They dominate the land for a few years, then succumb to competition from other plants, including the grasses. When they bloom, they stretch from Manitoba to northern Mexico and provide a nectar path for migrating monarch butterflies, as well as a steady diet for the more sedentary silvery checkerspots.

These are precious weeks when life is suspended between summer and winter. Heath asters may attract stinging insects, but they have no inhibitions about blooming until frost. We can’t all travel on. Those of us who stay around, deserve our pleasures too.

Notes:Clayton, Paul. "Gotta Travel On;" Bob Colton discusses the origins of the song in Paul Clayton and the Folksong Revival, 2008.

Hilty, John. "Heath Aster," Illinois Wildflowers website has more details on insects.

Smith, Huron H. "Ethnobotany of the Meskwaki Indians," Public Museum of the City of Milwaukee Bulletin 4:175-326:1928, cited by Dan Moerman, Native American Ethnobotany, 1998.

Photograph: Heath aster with wasp on cloudy day, 16 September 2009; brown sweet pea pods in back.

Autumn Joy Sedum

What’s blooming in the area: Tamarix, tea roses, Apache plume, trumpet creeper, Japanese honeysuckle, silver lace vine, leather leaved globemallow, alfalfa, white sweet and white prairie clovers, velvetweed, scarlet beeblossom, white and yellow evening primroses, datura, Heavenly Blue and ivy-leaf morning glory, scarlet creeper, bindweed, goats’ head, purple phlox, bouncing Bess, pale trumpet, stickleaf, clammy weed, spurge, pigweed, Russian thistle, winterfat, ragweed, snakeweed, native and farmer’s sunflowers, áñil del muerto, Hopi tea, horseweed, wild lettuce, purple, heath, strap-leaf and hairy golden aster, goldenrod, tahokia daisy, pampas grass; tiny apricots and apples coming down; red peppers and ripe watermelon.

What’s blooming in my yard, looking north: Zucchini, nasturtium, Mexican hat, chocolate flower, blanket flower, black-eyed Susan, chrysanthemum.

Looking east: Hosta, California and Shirley poppies, hollyhock, winecup, sidalcea, snapdragons, Maltese Cross, Jupiter’s beard, large-leaved soapwort, Autumn Joy sedum, garlic chive, Maximilian sunflower.

Looking south: Blaze roses, rose of Sharon, sweet pea, Crimson Rambler and reseeded morning glories, zinnia, cosmos.

Looking west: Caryopteris, butterfly bush, Russian sage, catmint, calamintha, lady bells, flax, sea lavender, David phlox, leadplant, perennial four o’clock, purple ice plant, Silver King artemisia, purple coneflower, Mönch aster; peaches falling.

Bedding plants: Moss rose, sweet alyssum.

Inside: South African aptenia.

Animal sightings: Rabbit, geckos, bees, large black harvester and small dark ants, grasshoppers.

Weather: Rain in area all week, but all I got was late afternoon clouds; last night not enough water fell to dampen the surface; last real rain 8/30/09; 13:45 hours of daylight today.

Weekly update: My Autumn Joy sedum is now at the stage where the rose red, five-petaled flowers attract bees.

The three plants formed new basal rosettes of pale, scalloped leaves in early March. The single, stout stems emerged in early July. The fattening buds, held in flat clusters like yarrow, showed streaks of white when the protective sepals were forced apart later in the month. Two weeks ago the florets started to open a pale pink, and now the tips are darkening.

The perennial’s not only one of the more colorful fall flowers, but also a sign of nature's ability to survive the worst that the climate or man can contrive.

In 1863, the ambitious son of a silk worker, Friedrich Bayer, and master dyer Johann Friedrich Weskott opened a factory in Barmen to produce synthetic dyes from coal tars. Eight years after Bayer died, Georg Arends opened a nursery in Ronsdorf on the same Rhine tributary in 1888.

Chemists were then improving upon nature by taking known, discrete elements and mixing them to see what would result. Ten years before Bayer changed from selling dyes to manufacturing them, Charles Frederic Gerhardt combined acetyl chloride with a sodium salt of salicylic acid to produce a synthetic form of the white willow bark then used to treat fever and inflammation. In 1897, a Bayer chemist, Felix Hoffmann, found a way to produce acetylsalicylic acid in a stable form that could be mass produced as aspirin.

Breeders were applying the same methods to nature. In the early 1900's, Arends began introducing new varieties of astilbe that crossed at least four species. In the 1920's, he was experimenting with sempervivums, another succulent in Autumn Joy's Crassula family. And in 1939, the same year Hitler invaded Poland, he introduced a new hybrid heath, Silberschmelze.

In the same years, Bayer was assimilated into I.G. Farbenindustrie, and the towns of Barmen, Ronsdorf and Elberfeld, where Bayer had moved its operations, were merged into Wuppertal, a major rail and heavy industrial complex spread along the banks of the narrow Wupper river valley. Beginning the night of May 29, 1943, the British sent 719 planes to drop 1,900 tons of bombs on the area. 2,450 civilians died, Bayer was out of production for nearly two months, and Arends' nursery was destroyed.

Julia Brittain says Arends, then nearly 80, never fully recovered. Paul Temple landed with the D-Day invasion of June 6, 1944, and remembered helping the crippled nursery smuggle seedlings to Harold Hillier in England.

After the war, Arends' two sons kept the operation running. In 1950, the old man began working with a dwarf azalea seedling. Then in 1955, three years after he died, Herbsfreude was released as a hybrid between Sedum spectabile, a pink-flowered ornamental from the lowlands of northeastern China and Korea, and Sedum telephium maximum, a highly variable European native.

In the middle sixteenth century, Hieronymus Bock had reported extracts of telephium were used in the Rhine valley to treat internal injuries like ulcers of the lungs. A century later, Nicholas Culpeper said a bruised leaf or the sap from orpine was used in England to treat external wounds. However by the time, Georg Arends was active, the old herbal remedies, like the dye plants, had been displaced by chemists.

Now, medical researchers are isolating the active ingredients from those traditional medicine plants and testing their efficacy. In the early 1990's, researchers in Munich identified two polysaccharides in telephium that were anti-inflammatory. A few years later, Italian scientists observed the ways the polysaccharides and flavonols operated on cells during wound healing. Last year, another Italian group described the biochemical processes involved in abating inflamation.

Bayer may have reemerged from Allied control in 1951 a much smaller company, but it has since reconglomerated, and now even makes the lawn pesticide sold in the local hardware that uses synthetic pyrethrum. Arends' granddaughter, Anja Maubach, still has the nursery in Ronsdorf. Herbsfreude is sold as Autumn Joy, and botanists have decided that spectabile and telephium aren’t really sedums after all, but members of a related genus they call Hylotelephium.

Notes:Altavilla, Domenica, Francesca Polito, Alessandra Bitto, Letteria Minutoli, Elisabetta Miraldi, Tiziana Fiumara, Marco Biagi, Herbert Marini, Daniela Giachetti, Mario Vaccaro, Francesco Squadrito. "Anti-Inflammatory Effects of the Methanol Extract of Sedum telephium ssp. maximum in Lipopolysaccharide-Stimulated Rat Peritoneal Macrophages," Pharmacology 82:250-256:2008.

Bock, Hieronymus. Kräuterbuch, 1539, cited by Culpepper.

Brittain, Julia. The Plant Lover’s Companion, 2006.

Culpeper, Nicholas. Culpeper’s Complete Herbal and English Physician, 1650's, 1826 edition republished in 1981.

Obituary for Paul Temple, The Telegraph, 24 February 2007.

Raimondi, L., G. Banchelli, D. Dalmazzi, N. Mulinacci, A. Romani, F. F. Vincieri, and R. Pirisino. "Sedum telephium L. Polysaccharide Content Affects MRC5 Cell Adhesion to Laminin and Fibronectin," Journal of Pharmacy and Pharmacology 52:585-591:2000.

Sendl, A, N. Mulinacci, F. F. Vincieri, and R. Wagner. "Anti-inflammatory and Immunologically Active Polysaccharides of Sedum telephium," Phytochemistry 34:1357-62:1993.

Photograph: Autumn Joy sedum, 7 September 2009.

Clammy Weed

What’s blooming in the area: Tamarix, tea roses, Apache plume, trumpet creeper, Japanese honeysuckle, silver lace vine, leather leaved globemallow, alfalfa, white sweet and white prairie clovers, velvetweed, scarlet beeblossom, white and yellow evening primroses, datura, Heavenly Blue and ivy-leaf morning glory, scarlet creeper, bindweed, goats’ head, purple phlox, bouncing Bess, pale trumpet, stickleaf, clammy weed, spurge, purslane, pigweed, Russian thistle, amaranth, winterfat, ragweed, snakeweed, native and farmer’s sunflowers, áñil del muerto, Hopi tea, gumweed, horseweed, wild lettuce, purple, strap-leaf and hairy golden aster, woolly paper flower, goldenrod, tahokia daisy, black grama grass; buds of heath asters; seeds on bittersweet and burr grass; some corn stalks turning brown; grass and alfalfa hay cut; apples falling.

What’s blooming in my yard, looking north: Zucchini, nasturtium, Mexican hat, chocolate flower, blanket flower, black-eyed Susan, chrysanthemum.

Looking east: Floribunda rose, hosta, California and Shirley poppies, hollyhock, winecup, sidalcea, snapdragons, Maltese Cross, Jupiter’s beard, coral beardtongue, large-leaved soapwort, sedum, garlic chive, Maximilian sunflower.

Looking south: Blaze roses, rose of Sharon, sweet pea, Crimson Rambler and reseeded morning glories, zinnia, cosmos.

Looking west: Caryopteris, butterfly bush, Russian sage, catmint, calamintha, lady bells, flax, sea lavender, David phlox, leadplant, perennial four o’clock, purple ice plant, Silver King artemisia, purple coneflower, Mönch aster.

Bedding plants: Moss rose, sweet alyssum; ripe tomatoes.

Inside: South African aptenia.

Animal sightings: Rabbit, geckos, hummingbird, bees, large black harvester and small dark ants, grasshoppers.

Weather: Rain last rain Sunday; 13:05 hours of daylight today.

Weekly update: When clammy weed began blooming the end of July it resembled phlox, a round white head topped a tall, straight stem that rose from a bed of three-part, clover-like leaves.

Now it’s been out for more than a month it looks more like mustard. The individual florets terminate maroon stems that reach up and out from narrow leaves. Each flower begins as a collection of four white petals surrounding a purple pistil like ancient megaliths held tight into the head. A fountain of purple stamens towers above.

The central stem continues to grow, and after the flowers are fertilized, the petals fall away leaving the stamens and ovary which become isolated from the head. Soon, they’re replaced by a green pod held out by the pedicel branch dropping under the weight until the plants looks like one of those many armed Hindu gods.

This member of the caper family ranges from lower Canada to the upper states of México, but it isn’t ubiquitous. John Hilty says that in Illinois the taprooted annual occurs on "sand or gravel bars along rivers, gravelly areas and clay banks along railroads, and barren waste areas." In Michigan, Edward Voss reported it grew in the southern counties with glacial till.

To the southwest of Española, the Nature Conservancy reports clammy weed grows with stickleaf species on intermittently flooded, sometimes stony alluvial flats and sandbars in central and southern Arizona where other herbaceous plants are scarce. In southern New Mexico, it’s found with local stickleaf species, datura and agave where shrubs have replaced grasses on the Jornado plain.

The nearby wide arroyo where I see the flowers runs west to the Rio Grande. The south wall is maybe seven feet high and relatively soft clay or sandy loam. A wide plain has developed at its base, edged by chamisa where the water runs. The wildflowers blooming there now include golden hairy asters and hopi tea.

The north bank is higher, with openings carved by wind and water. Bands of exposed gravel spill out, so the near floor is pebbly in places. Russian thistle and stickleaf sprouted in its shadow when the weather warmed. Clammy weed’s only found in this protected area, except for one plant that emerged in the middle of the road cut.

Despite the wide national distribution, the only native groups Dan Moerman reports using clammy weed live in Arizona and New Mexico. The Isleta south of Albuquerque rolled dried leaves in corn husks for ceremonial cigarettes while the cactus fraternity of the Zuñi rubbed chewed a’pilalu roots and flowers on wounds after members were whipped by willow and cactus switches.

It’s limited use by tribes may be a function of the sporadic nature of a summer annual that depends on soil, rain and temperature conditions to germinate, or it may result from the natural protection of the plant. The leaves and stems are sticky and stink.

Qian Shi’s team at the University of North Carolina has been testing chemicals they’ve extracted from Polanisia dodecandra and found at least one is effective against a number of types of cancer cells, and another is somewhat effective. If it weren’t for all these chemicals, the plant that’s growing into a robotic toy soldier might better be known as red whiskers.

Notes:
Association for Biodiversity Information/The Nature Conservancy. "International Classification of Ecological Communities: Terrestrial Vegetation of the Western United States, Chihuahuan Desert Subset," May 23, 2000 draft available on-line.

Hilty, John. "Clammyweed," Illinois Wildflowers website.

Moerman, Dan. Native American Ethnobotany, 1998, summarizes data from a number of ethnographies including Volney H. Jones, The Ethnobotany of the Isleta Indians, 1931.

Shi, Q., K.Chen, L. Li, J. J. Chang, C. Autry, M. Kozuka, T. Konoshima, J. R. Estes, C. M. Lin, and E. Hamel. "Antitumor Agents, 154. Cytotoxic and Antimitotic Flavonols from Polanisia dodecandra," Journal of Natural Products 58:475-82:1995.

Stevenson, Matilda Coxe. Ethnobotany of the Zuñi Indians, 1915.

Voss, Edward G. Michigan Flora, volume 2, 1985.

Photograph: Clammy weed in arroyo road cut, 30 August 2009.

Ragweed

What’s blooming in the area: Tea roses, Apache plume, butterfly bush, trumpet creeper, Japanese honeysuckle, silver lace vine, leather leaved globemallow, sweet pea, alfalfa, white sweet clover, Russian sage, velvetweed, scarlet beeblossom, white and yellow evening primroses, datura, Heavenly Blue and ivy-leaf morning glory, scarlet creeper, bindweed, goats’ head, purple phlox, bouncing Bess, pale trumpet, stickleaf, clammy weed, spurge, purslane, pigweed, Russian thistle, winterfat, ragweed, snakeweed, native and farmer’s sunflowers, Hopi tea, gumweed, horseweed, wild lettuce, strap-leaf and hairy golden aster, woolly paper flower, goldenrod, tahokia daisy, black grama grass; buds of heath and purple asters; new áñil del muerto plants.

What’s blooming in my yard, looking north: Zucchini, nasturtium, Mexican hat, chocolate flower, blanket flower, black-eyed Susan, chrysanthemum.

Looking east: Floribunda rose, California poppy, hollyhock, winecup, sidalcea, snapdragons, Maltese Cross, Jupiter’s beard, coral beardtongue, large-leaved soapwort, scarlet flax, sedum, garlic chive, Maximilian sunflower.

Looking south: Blaze roses, rose of Sharon, Crimson Rambler and reseeded morning glories, zinnia, cosmos.

Looking west: Caryopteris, flax, catmint, calamintha, lady bells, sea lavender, David phlox, leadplant, perennial four o’clock, purple ice plant, Silver King artemisia, purple coneflower, Mönch aster; some peaches survived the spring frosts.

Bedding plants: Moss rose, sweet alyssum, tomato.

Inside: African aptenia and asparagus fern.

Animal sightings: Rabbit, geckos, hummingbird, bees, large black harvester and small dark ants, grasshoppers.

Weather: Continued hot afternoon winds and late clouds rather than usual monsoons; last rain 8/24/2009; 13:41 hours of daylight today.

Weekly update: Somehow, from bits of urban legends, facts half remembered from grade school, and trivia passed on at summer camp or, later, by friends at work, we cobble together a collection of facts about the natural world we absolutely believe to be true.

Everyone knows cockroaches are older than dinosaurs and ginko trees are the oldest living fossils. I had my own idea that plants like ragweed with male and female green flowers so inconspicuous they could only be pollinated by the wind were nearly as old as the ginko.

We cede these survivors of the cataclysm that destroyed the dinosaurs great powers of adaptation.

And sometimes we’re at least partly right. Cary Easterday found a nearly complete fossil of a giant cockroach from the 300 million-year-old Carboniferous layers of an eastern Ohio coal mine in 1999 that predates the dinosaurs. However, it’s closer to the insects found today in the tropics than to our domestic insect which comes from the Cretaceous that followed the extinction of the giant reptiles. It’s the genus that’s ancient, not the species.

Ragweed, like cockroaches inhabiting city apartments, will not be killed. Increase the carbon dioxide in the air and it still germinates. Throw salt on the road in winter and ecotypes germinate before the salt’s disappeared from the soil. Mow it down and it comes back in two weeks with flowering stalks below the level of a blade.

Spray it with herbicides, it develops strains resistant to Round-up and ALS inhibitors. Give it a hard spring that won’t encourage growth, the seeds resume dormancy and can wait 20 years to germinate. Let the surrounding vegetation get too luxurious, it produces short, female-only plants that go to seed.

Well, plasticity’s the only part about ragweed that fits the naturalist’s equivalent of an old wive’s tale. Ambrosia artemisiifolia, in fact, is a member of the composites, one of the more recent plant families, dating to sometime in the Cretaceous, the era before our modern continents formed when bees were just emerging Ginko fossils go back to the Permian, that geologic time between the Carboniferous of the giant cockroach and the Triassic of the dinosaurs.

Ragweed was one of the first plants I could distinguish as a child by its determined geometricalness. The divided, grey-green leaves spread parallel to the ground and at ninety degrees to each other. Later in the season the leaves changed shape and location, but by then I recognized the tapering flower spikes that looked like the square weave on a lanyard with openings between each layer where green caps repeated the pattern of the lower leaves.

Because I could identify the plant from a distance, I never bothered to look at it closely. This year’s unusual mix of rain, heat, and cold may have encouraged the flowers to expand more than usual to interrupt the expected color pattern. Last Sunday was the first time I ever saw a reason to pick a spike.

Under the green heads of five sepals, that cover the flower clusters before they’re ready to bloom and give the upper spikes their green appearance, is a round yellow bud, surrounded by a single ring of similar buds. There looked to be six or seven outer buds near the base of the spike, but maybe four toward the top. Along the spike, only a few of the male flowers had three anthers pointing down to release the hay fever causing pollen.

I was somewhat gratified to discover scientists can be as fooled by their early assumptions as lay people like me. Although they know the pollen can blow for miles, botanists have always assumed the grains dropped directly down to the female flowers placed where the leaves join the stem. Then, Jannice Friedman and Spencer Barrett watched some ragweed flowers and found most of the female flowers aborted if they detected pollen from their own plant and plants grown in isolation produced far fewer hard seeds than those au naturel.

But even then they realized the common ragweed would adapt. Deprive them of the pollen they need, and they’ll overcome their self-incompatibility to make do with what appears. No one yet has proven the green weed won’t survive Armageddon.

Notes:
360-286m - Carboniferous - hot - oldest cockroach - evergreens
286-248m - Permian - glaciers in southern hemisphere - more insects - deciduous trees - ginko
248-213m - Triassic - hot and dry - Gondwana breaks away - dinosaurs - ferns
213-144m - Jurassic - seas advance - dinosaurs - earliest birds and flowers
144-65m - Cretaceous - swamps - dinosaurs extinct - bees - modern cockroach - composites
65m-2m - Tertiary - drier - modern continents form - sea animals - grasses
2m- - Quarternary - glaciers come and go - modern animals and plants

Bazzaz, Fakhri A. "Ecophysiology of Ambrosia artemisiifolia: A Successional Dominant," Ecology 55:112-119:1974.

_____. Plants in Changing Environments, 1996.

Friedman, Jannice and Spencer C. H. Barrett. "High Outcrossing in the Annual Colonizing Species Ambrosia artemisiifolia (Asteraceae)," Annals of Botany 101:1303-1309:2008.

Lee, Chad, Karen Renner and Jim Kells. "ALS- Resistant Common Ragweed in Michigan," Michigan State University Field Crop Advisory Team Alert for 23 March 2000.

Lundholm, J. T. and L. W. Aarssen. "Neighbour Effects on Gender Variation in Ambrosia artemisiifolia," Canadian Journal of Botany 72:794–800:1994.

Ohio State University. "Largest Fossil Cockroach Found; Site Preserves Incredible Detail," news release, 7 November 2001.

Pollard, Justin Michael. "Identification and Characterization of Gylphosate-Resistant Common Ragweed (Ambrosia artemisiifolia L.), University of Missouri-Columbia, 2007.

Antonio DiTommaso. "Germination Behavior of Common Ragweed (Ambrosia artemisiifolia) Populations across a Range of Salinities," Weed Science 52:1002-1009:2004

Photograph: Ragweed growing along the road by my house, 23 August 2009; most are buds, but it looks like the anthers are extended on one flower to the left of the stem above the long leaf.