Sunday, March 27, 2011

Crocus

What’s blooming in the area: Forsythia, first daffodil flowers are shorter than usual; new leaves on weeping and globe willows, Japanese honeysuckle, village ditch meeting today.

Outside the walls and fences: Buds forming on cottonwoods; new leaves on Siberian elm seedlings, winterfat, alfilerillo, cheese mallow; first pigweed seedlings up; sooner or later all conversations turn to juniper allergies.

In my yard: Oxalis, dandelion; buds on hyacinth; cherry buds expanding, outer skin splitting to show green; Madonna lily leaves turning green; new leaves on Persian rose, large and small leaved soapworts, blue flax; new raspberries, pasture roses and daylilies coming up.

Inside: Pomegranate; new growth and buds on zonal geraniums.

Animal sightings: Rabbit; ants are back, black and red, big and little.

Weather: Clouds at daybreak, winds in afternoon; snow lingers in Sangre de Cristo; last rain 3/8/11; 12:29 hours of daylight today.

Weekly update: Every year, my one, still tightly buttoned up crocus pokes through and decides, like a good Church of Christ congregant, that this world is not its home. It retreats to life underground, producing only the leaves necessary to feed the new corm. It never wastes any energy on flowers.

While Christians know their treasures are being “laid up somewhere beyond the blue,” the home of Crocus vernus is more obscure.

The species grows in mountainous areas of Europe from Spain to Albania and north into Poland. Researchers in Italy found the plants appeared most often with a tall bunch grass, Nardetea stricta.

French scientists wondered about the association of some plants, like the mat grass and early blooming crocus, with soils containing silicon, rather than lime, and concluded the soil was less important than the fact that limestone absorbs more water than the underlying gneiss, and thus leaves less for the roots.

The actual home of the cultivar I planted in 2006 is a strip of siliceous sand dunes bordering the North sea in Nord-Holland. W. J. Elderly founded his nursery there in Overveen in 1853. It introduced my silvery purple Grand Maître in 1924, the purple Remembrance in 1925, the white flowered Jeanne d’Arc in 1943, and soon after the purple and white stripped Pickwick.

In 1880, the nursery had introduced King of the Stripped.

The bulb trade is generally associated with Haarlem to the east. After the end of the Napoleonic wars, demand increased while the planting regimes had been somewhat disrupted. Growers began looking for new, less valuable land to use to grow bulbs for the first years before they were large to plant in Haarlem to impress the market buyers.

They had the best success in areas where light sand lay over a water table 15 to 30 inches below. Those grounds at Overveen had been used by Flemish linen bleachers, but that trade had been in decline and men there were looking for new sources of income.

Gerrett Eldering was one of the more successful local growers. In 1817, he was still bleaching linen, but had also begun to grow the lucrative hyacinth, tulip and narcissus which so depleted the fragile soil, they could only be grown every two or three years. In the intervening seasons, he planted market vegetables. Crocuses required so little time in the ground, he could get a crop of potatoes the same year.

Even with the vegetable layer dug into the sand, Eldering added a coating of manure diluted in water. His fields were bounded by hedges which stopped the wind from removing the soil and shredding the leaves necessary to the bulbs’ maturation.

Field rotation was still in use in 1909, when Una Silberrad visited them. The vagaries of climate were controlled by layers of straw which were put down before winter, then removed and replaced when temperatures warmed in the spring to keep the bulbs cool in the ground.

Nature, of course, uses those bunch grasses for the same effect. The dead litter covers the bulbs in winter. Some try to reproduce that effect by planting their corms in lawns, but J. N. Garard warned they probably would be crowded out by the grass in a few years.

Sandy Snyder had better success in Littleton, Colorado, where she planted bulbs in a tufted buffalo grass yard that was still brown in spring when the bulbs needed the water. Unlike Gerrett Eldering, who employed a crew of men and boys to remove the soil, carefully lay the bulbs on the flat, open ground, then cover them with sand from the next bed to be planted, she used her family. One created the hole, the second dropped the bulb, and the third filled the hole.

He, of course, had to pay his men, while she probably only needed to feed her helpers. Poor Christians in the song are satisfied with assured, delayed payments where they’ll live eternally with the “saints on every hand.”

Notes: “This World Is Not My Home,” is an old Church of Christ gospel song recorded by many with variants copyrighted by many, including Albert E. Brumley. Kristen Hamilton discussed the song’s history on the HomeschoolBlogger website on 16 July 2009.

Costanzo, Emanuele, Francesco Furnari, and Valeria Tomaselli. “A Phytosociological Survey of the Main Plant Community Types of Alpine and Sub-alpine Belt in the Sibillini Mountains (Central Apennines, Italy),” Lazaroa 30: 219-250:2009.

Garard, J. N. "Crocus" in Liberty Hyde Bailey, The Standard Cyclopedia of Horticulture, volume 2, 1914.

Loudon, John Claudius. An Encyclopædia of Gardening, volume 1, 1835, describes an article by Knight published by The Garden.

Michalet, Richard, Cécile Gandoy, Didier Joud and Jean-Philippe Pagès. “Plant Community Composition and Biomass on Calcareous and Siliceous Substrates in the Northern French Alps: Comparative Effects of Soil Chemistry and Water Status,” Arctic, Antarctic and Alpine Research 34:102-113:2002.

Neill, Patrick. Journal of a Horticultural Tour Through Parts of Flanders, Holland, and the North of France in the Autumn of 1817, 1823.

Silberrad, Una Lucy and Sophie Lyall. Dutch Bulbs and Gardens, 1909, illustrations by Mina Nixon.

Snyder, Sandy. “Splendor in the Grass,” Fine Gardening 24-28:May/June 1990; she planted other crocus species than vernus.

Zwollo, Tonny. “Oldenhove,” in Blue Is My Colour, Designing as an Answer to Nature, 2005, on the history of Overneen.

Photograph: Grand Maître crocus, 21 March 2011.

Sunday, March 20, 2011

Bearded Iris

What’s happening: People planting new trees; continued to trim trees, clean ditches and burn along fences; arborvitae recovering; rose branches turning green; new leaves on tulips, bearded iris, hyacinths, garlic chives, Autumn Joy sedum, vinca, bouncing Bess, white sweet clover, alfalfa, Mexican hat, broom senecio and pampas grass; new anthemis seedlings; dead pigweeds breaking loose; pet garlic back; green showing in leaf buds of lilacs.

What’s green: Evergreen, yucca, grape hyacinth, oriental poppy, hollyhock, Jupiter’s beard, small leaved soapwort, gypsum phacelia, yellow and pink evening primrose, winecup, tansy and tumble mustard. broom senecio, snakeweed, dandelion, black-eyed Susan, and chrysanthemum leaves; June, cheat and needle grass.

What’s grey, blue-grey or grey-green: Piñon, four-winged salt bush, stickleaf, yellow alyssum and winterfat leaves; new leaves on loco; stickleaf seedlings emerging.

What’s red/turning red: Cholla, Madonna lily, golden spur columbine, beardstongue, creeping mahonia leaves; young tamarix stems; apple tree branches look redder.

What’s yellow/turning yellow: Leaf buds laying along branches of globe willows, pulling away into independent leaves on weeping willow; forsythia buds showing bright green.

What’s blooming inside: Bud on pomegranate; new growth on zonal geraniums.

Animal sightings: Rabbit; quail in uphill neighbor's yard; smaller birds are back, including a pair that’s eyeing my back porch.

Weather: Warm afternoons with winds and no moisture; snow lingers in Jemez and Sangre de Cristo; last rain 3/8/11; 12:09 hours of daylight today.

Weekly update: New bearded iris leaves are emerging through the remains of last year’s dead debris. In a few cases, old leaves are being pushed up by new growth.

In milder climates the plants retain their color all year. William Dykes took that as an indicator that Iris germanica was native to a warmer climate than England, one nearer the Mediterranean. He also noted the flowers sometimes failed in his area when cold in March or April killed the rudimentary flowering stems, still buried in the leaves.

The Española valley isn’t particularly congenial to the cultivars offered by most nurseries. Many I’ve planted didn’t make it through the first winter. Others petered out after several seasons. Only a few have actually expanded into clumps. Last year almost none bloomed after snow fell in late March and again the end of April.

When I first moved here in 1991, most of the iris I saw were yellow. Then I noticed some blue flowers, perhaps ones I’d ignored earlier because they were too familiar from elsewhere. Most recently, I’ve seen pastels and mixed lots of color in other people’s yards.

I don’t know if the changes in flower color reflect a change in taste, infilling by outlanders with different preferences, or a shared desire by gardeners to grow iris that is limited by what’s sold by local hardware stores and big boxes.

The reason I suspect people’s palettes reflect enduring cultural preferences is that one of my Spanish-speaking neighbors told me, with a nod towards heaven for protection, that he’d dug his yellow iris from a cemetery. The funereal plants may represent nothing more than the ability of one variety to survive where others did not, but the effort to bring them home bespeaks desire.

I also suspect that when Anglos look at German iris we evoke different cultural categories than do the Spanish-speaking natives. In the late 1940's. Leonora Curtin was very much puzzled when she was told the plants were called lirio, which she knew to refer to lilies, and heard the roots were poisonous. She knew the last couldn’t be true, because the rhizomes had long been used to treat dropsy and bowel problems.

The confusion may have arisen from the fact that the flowers of all members of the Iris genus look alike, three petals cupped upwards and three pointing down. They may or may not have beards, may grow from bulbs or rhizomes, may have wide or narrow leaves. It doesn’t matter. Everyone knows by the flowers they are iris and uses that term. If more is needed, most use color to distinguish one from another.

When Dioscorides discussed the medicinal uses of irises by the Greeks, he said they were the ones with varied colors. Similarly, when Pliny described the ones the Romans used in medicine, he distinguished them from others by their rainbow of colors. Neither warned against any poisonous ones.

If yellow is the preferred color, then people here may be thinking of the wetland Iris pseudacorus when they look at the flowers of the commercially available plants, not the dryland germanica. A recent blog posting from the Estramadura, home of the conquistadores, says lirio amarillo grows along the Guadiana river in Spain’s Badajoz province and is easy to find in villages where it is considered tóxica.

The source of the poison has never been determined, but Dietrich Frohne and Hans Jürgen Pfänder report, when the leaves are dried in hay, they can cause severe diarrhea in cattle. They also note “no relevant observations have been reported in recent times.”

The question for the anthropologically inclined is how a term and a perception of danger could have passed through generations in an area where yellow iris don’t grow. The answer again is that it didn’t matter what kind of iris was growing, so long as it was some iris that could be used to perpetuate folk knowledge.

The medium may have been cemeteries like the one visited by my neighbor. It would be easy to latch on to the fact that Moslems plant white iris on graves to draw some facile inferences. After all, Dykes says the Spanish took Iris albicans into the Sierra Madre of México where silver was mined.

However, German iris are so durable, so tolerant of neglect, they’re been used everywhere in graveyards in this country, especially by people who want something that blooms on Memorial Day. Their funeral use is a constant reinvention.

In the far south of the state, Robin Nutt recorded all the burials in the Spanish-speaking community’s San Jose cemetery in Las Cruces. When nothing survived, she listed whatever remained to indicate a body lay below. In many cases, it was a cross or cement perimeter, but in two cases it was flowers and in seven it was iris. She noted no other plants except some large trees which sheltered graves of two Sloan sisters and a Buergo who married a Sullivan.

Perhaps their persistence as the last relics of now unmarked graves explains why men who work on my property, who treat all plants as things to be exterminated, stop when they notice iris leaves and walk around. Memento mori command respect from both plantsmen like my neighbor and those with less regard for nature.

Notes:Curtin, Leonora Scott Muse. Healing Herbs of the Upper Rio Grande, 1947, republished 1997, with revisions by Michael Moore.

Dioscorides, Pedanius. De Materia Medica, translated by Tess Anne Osbaldeston, 2000.

Dykes, William Rickatson. The Genus Iris, 1913, reprinted by Dover, 1974.

Frohne, Dietrich and Hans Jürgen Pfänder. Poisonous Plants: a Handbook for Doctors, Pharmacists, Toxicologists, Biologists and Veterinarians, 2005.

Jiménez, José Antonio. “Iris pseudacorus,” Flora de Mérida website, 27 November 2010.

Nutt, Robin. “Dona Ana County, New Mexico-St. Jose Cemetery, Las Cruces,” at USGenWeb..

Pliny the Elder (Gaius Plinius Secundus). Naturalis Historia, translated by John Bostock and Henry Thomas Riley, 1856.

Photograph: Blue flowered bearded iris, 17 March 2011.

Sunday, March 13, 2011

Needle Grass

What’s happening: New leaves on oriental poppies, south facing hollyhocks, dandelions and June grass; small leaved soapwort and yellow evening primrose leaves turning green.

What’s green: Evergreen, yucca, grape hyacinth, Jupiter’s beard, gypsum phacelia, pink evening primrose, winecup, tansy and tumble mustard. broom senecio, snakeweed, black-eyed Susan, chrysanthemum leaves; cheat and needle grass.

What’s grey, blue-grey or grey-green: Piñon, four-winged salt bush, stickleaf, yellow alyssum and winterfat leaves.

What’s red/turning red: Cholla, Madonna lily, golden spur columbine, beardstongue, creeping mahonia leaves; rose and young tamarix stems.

What’s yellow/turning yellow: Globe and weeping willow branches.

What’s blooming inside: Bud on pomegranate; new growth on asparagus fern

Animal sightings: Rabbit; small brown birds back in peach.

Weather: Clouds that hovered for several days finally dropped some water Monday night; snow lingers in Jemez and Sangre de Cristo; 12:09 hours of daylight today.

Weekly update: The first sign of spring on the prairie is new growth at the base of the needle grass. Sandy brown tops still dominate the horizon, but new shoots are emerging among stalks that themselves are greening below.

Even so, there’s probably more going on underground than above at this time. As the perennials increase their photosynthesis, mycorrhizal fungi gather round the roots to absorb carbon. In exchange, they pass through phosphorus they’ve extracted from the soil that’s needed by the grass to produce DNA, RNA, cell walls and energy transport systems.

The symbiosis is as old as land plants. They’ve found fossils of fungus associated with other plants in the Rhynie chert beds of Scotland that date back 400 million years ago. By the Miocene, when grasses were emerging, the mycorrhizae had assumed their modern form. Hesperostipa comata migrated from the neotropics into our region before the end of that era.

While the cool season bunch grass is dependent on the existence of the small organisms, the range of the fungi is limited by the presence of phosphorus. The structure of the plants varies by the amount of the available mineral. However, they cannot tolerate the high levels introduced by farmers.

The fungi also die when animals eat the blades, thereby decreasing the volume of carbon fed to them. Gabor J. Bethlenfalvay and Suren Dakessian compared plants growing in adjacent protected and unprotected areas on a recovering range. They found leaves on grazed plants only appeared around the perimeter of the crown, while uneaten plants produced full tufts with “hundreds of well developed leaf blades.”

They also found phosphorus levels were lower in the ungrazed soil, a measure of the presence of vesicular-arbuscular mycorrhizal fungi. When the tiny organisms disappear, there’s nothing left to provide vital nutrients. The shallow, fibrous roots decline in weight, though not as much as the greens they support.

Ranchers are told it’s safe to graze their animals on needle grass in early spring, when it’s one of the earliest plants available, and again in fall, when it’s resumed growth after the monsoons. The stalks cure well, and are considered good winter feed.

Most cattle and sheepmen move their animals when seeds develop in late spring, usually early May here. Not only do the seeds have harpoon points that break off when they embed themselves in skin and wool, but they’re carried by long tails that twist with moisture.

After the seeds are ripe, the grasses go dormant during the heat, and their protein levels drop. It’s then that continued grazing destroys life above and below ground, to little benefit of the mammals.

Once the grass dies, it takes at least ten years to come back, even when carefully seeded and watered. After that initial period, stands still only expand slowly.

In my yard, the overgrazed sections may never revive. One reason may be that, despite the long life expectancy of the seed, not many actually accumulate in the soil. In addition, those seeds that do survive need cold to emerge and possibly fire. Robert Blank and James Young found seeds germinate better when the soil is heated more than 500 degrees or they are exposed to smoke.

Only some of those conditions will be met here.

Notes:
Bethlenfalvay, Gabor J. and Suren Dakessian. “Grazing Effects on Mychorrhizal Colonization and Floristic Composition on a Semiarid Range in Northern Nevada,” Journal of Range Management 37:312-316 :1984.

Blank, Robert R. and James A. Young. “Heated Substrate and Smoke: Influence on Seed Emergence and Plant Growth,” Journal of Range Management 51:577-583:1998.

Dick-Peddie, William A. New Mexico Vegetation, 1993, on needle grass as neotropic-tertiary flora.

Wikipedia. On-line entry for “Arbuscular Mycorrhiza.”

Zlatnik, Elena. “Hesperostipa comata,” 1999, in United States Forest Service, Fire Effects Information System, available on-line.

Photograph: Needle grass at the edge of my drive with greening stalks and new sprouts, 12 March 2011.

Sunday, March 06, 2011

Pink Evening Primrose

What’s happening: First flush of green from bases of needle grass and my neighbor’s globe willow; Russian thistles on the move; Russian olive, juniper and pyracantha berries persist.

What’s still green: Evergreen, yucca, grape hyacinth, Jupiter’s beard, gypsum phacelia, pink evening primrose, broom senecio, snakeweed, chrysanthemum leaves; some grasses; new leaves in black-eyed Susan rosettes; winecup, tansy and tumble mustard germinating.

What’s grey, blue-grey or grey-green: Piñon, four-winged salt bush, yellow alyssum and winterfat leaves; stickleaf germinating.

What’s red/turning red: Cholla, Madonna lily, golden spur columbine, small-leaved soapwort, beardstongue, yellow evening primrose, creeping mahonia leaves; rose and young tamarix stems.

What’s yellow/turning yellow: Globe and weeping willow branches.

What’s blooming inside: Zonal geraniums.

Animal sightings: Hornet on inside porch; small birds out early on peach.

Weather: Warm afternoons chased off by cold winds; snow lingers in Jemez and Sangre de Cristo; last snow 2/4/11; 11:18 hours of daylight today.

Weekly update: Pink evening primroses fit the expectations of Spencerian ecologists who believe species are inherently aggressive and only kept in control by equally aggressive competitors.

Oenothera speciosa is native to tall grass prairies that stretch from Kansas and Missouri down through Texas into Coahuila and Chihuahua. Its branch of the Onagrace family developed in the Madrean Floristic region of today’s intermontane southwestern deserts during the Eocene when the Rockies were first being formed and grasses were evolving some 34 to 54 million years ago. The Oenothera diversified later to the east.

The five-petaled, cup-shaped flowers are white in the northern part of their range, but rosy purple with twice the chromosomes from central Texas south. In particularly hot summers here, they stop blooming in July, but resume with the monsoons and continue even after morning temperatures fall below 32.

The red anthocyanin pigments may be part of their defensive strategy against hostile conditions. The leaves turn burgundy in autumn. This past year some turned color the end of October, just before the hard freeze. More were red after temperatures fell below 20 in mid November. The stems connecting leaves to the crowns of some plants still have a reddish tint.

Despite the frigid winter, my plants kept some green leaves all winter under the protection of dead hollyhock leaves. They contain moderate levels of crude protein which deer and cattle don’t find particularly interesting in the summer. However, come winter, when little else is available, they’re palatable.

Buffalo don’t tend to eat them in summer, but they kill so many other plants with their hooves and mouths that the plants thrive. Their rhizomatous roots spread out into the newly barren areas which they quickly stabilize against the winds. They probably are choked out when the grasses reestablish themselves.

The ability to expand vegetatively is probably another adaption to life on the prairies. Grasshoppers eat the petals, sometimes before the flowers, which only live a day, can attract bees to pollinate them. As it is, the effectiveness of the bees decreases as they move from flower to flower, and the plants must be cross-fertilized to reproduce.

Temperature and day length controls their lives. Jelitto Seeds reports they germinate rapidly at about 68 degrees, then should be moved to a cooler location to grow. Beth Fausey and Art Cameron found nursery plants that spent five weeks at 40 degrees bloomed quickly, while those that weren’t vernalized would only bloom when days were 16 hours long.

For true Spencerians, the most dangerous thing anyone can do is introduce a species into a new environment where there are no natural predators. In the middle 1980's nurserymen were looking for new perennials for the new McMansion suburbs. Wayside Gardens offered its first Mexican evening primrose, Rosea, in 1987, while the more specialist Lamb Nurseries was already selling one as Berlandieri. In the early 1990's, Weiss Brothers added Siskiyou and Woodside White.

When the pink evening primroses were planted in areas where there’s more water like California and east of the Mississippi, the plants became pests. Garden websites are filled with complaints from people who treated them like other herbaceous perennials, only to have them overrun their beds and choke out the peonies, hostas and other more expensive, more cherished plants.

Before the complaints became loud, the species had become so popular with nurserymen, they were sold in the local hardware store in the early 1990's. One person in the village was able to nurture a row on the slope between a chain link fence and a dirt drive that got more than a foot high and were covered with pink flowers from mid May through summer.

I had more problems getting them established in my harsher environment. All the plants I bought, from whatever source, died. Most of the seeds I planted either didn’t germinate or were stolen by ants or birds. The fact my flowers are light pink with deeper colored veins may come from the climate or from the selection sold by Jelitto, the likely German source for the seeds I bought in 2004 and 2005. In 2006 seeds came from Oregon, the home of the Siskiyou mountains. Other years their origin was listed as Holland or the US.

The corollary to the theory of ecological balance is that plants, no matter how successful they may be, usually are unprepared for new threats. In 2003, some kind of metallic green beetle arrived in June. Hordes appeared after I got home in the evening and covered the wood fence, where I tried spraying them. Of course they moved off as soon as I appeared. My only hope was that the residue on the fence would kill or deflect them.

The only thing they ate was the evening primroses. The native white ones never came back, while the cultivated pink ones have only begun to stick their wiry stems up through the bearded iris since 2008. The planting by the village was decimated: a few flowers appeared in 2006 and 2007, then nothing since.

The neon ladybugs were probably primrose flea beetles. Around 2000 Altica litigata began to be reported in large numbers in the southeast. They invaded Dallas in 2002, and were here a year later. Some think they always existed in the wild in weedy Oenothera species that grew around nurseries. One group found, given a choice, they preferred Siskiyou to the natives.

The more confident Spencerians who believe man is the ultimate competitor think the only way to control an invasive species is to introduce its natural predator, preferably after some tests for unintended consequences. The army has been sponsoring research into the use of flea beetles against another member of the Onagraceae, the water primrose. The Uruguayan native has naturalized in the southeast, spread to Europe, and more recently been reported clogging inland waterways in New York and Washington.

One wonders if, when they were reading Principles of Biologu, they also chanced to read Oedipus.

Notes: For complaints, see comments at Dave’s Garden and Garden Web websites, or type in the plant name with the word invasive.

Damhoureyeh, S. A. and DC Hartnett. “Effects of Bison and Cattle on Growth, Reproduction, and Abundances of Five Tallgrass Prairie Forbs,” American Journal of Botany 84: 1719:1997.

Fausey, B. A. and A. C. Cameron. “Evaluating Herbaceous Perennial Species as New Flowering Potted Crops,” Acta Horticulturae 683:207-214:2005.

Freedman, Jan E., Michael J. Grodowitz, Robin Swindle and Julie G. Nachtrieb. “Potential Use of Native and Naturalized Insect Herbivores and Fungal Pathogens of Aquatic and Wetland Plants,” U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, report ERDC/EL TR-07-11, 2007.

Jelitto Staudensamen GmbH. Onothera speciosa on company website.

Jenkins, Tracie M., S. Kris Braman, Zhenbang Chen, Tyler D. Eaton, Gretchen V. Pettis, and David W. Boyd. “Insights into Flea Beetle (Coleopetra: Chrysomelidae: Galerucinae) Host Specificity from Concordant Mitochondrial and Nuclear DNA Phylogenies,” Entomological Society of America Annals 102:386-395:2009.

Katinas, Liliana, Jorge V. Crisci, Warren L. Wagner and Peter C. Hoch. “Geographical Diversification of Tribes Epilobieae, Gongylcarpeae, and Onagreae (Onagraceae) in North America, Based on Parsimony Analysis of Endemicity and Track Compatibilty Analysis,” Missouri Botanical Gardens Annals 91:159-185:2004.

McKenney, C. B., J. A. Reinert, and R. Cabrera. “Host Resistance of Oenothera spp. (Evening Primrose) and Calylophus spp. (Sun Drops) to the Flea Beetle, Altica litigata,” Southern Nursery Association Research Conference Proceedings 48:150-153:2003.

Ortega, Isaac M. Deer and Cattle Foraging Strategies under Different Grazing Systems and Stocking Rates, 1991.

_____, Sergio Soltero-Gardea and Fred C. Bryant. “Nutrient Content of Important Deer Forage Plants in the Texas Coastal Bend,” The Texas Journal of Science 46:133-142:1994.

Schultz, P. B. D. O. Gilrein, and M. S. Dills. “Flea Beetles Damaging Perennials,” Southern Nursery Association Research Conference Proceedings 46:190-191:2001.

Wolin, Carole L. Candance Galen and Lee Watkins. The Breeding System and Aspects of Pollination Effectiveness in Oenothera speciosa (Onagraceae),” Southwestern Naturalist 29: 15-20:1984.

Photograph: Pink evening primrose leaves surviving under dead leaves, 27 February 2011.