Sunday, March 28, 2010

Autumn Joy Sedum

What’s blooming in the area: Tansy mustard.

What’s growing: Moss, daffodils, daylily, loco weed, white sweet clover, pigweed, dandelion, hay; village ditch meeting yesterday.

What’s in my yard: Apache plume, first tulips, more hyacinths, garlic chives, Jupiter’s beard, bouncing Bess, Autumn Joy sedum, golden spur columbine, oriental poppies, anthemis, chrysanthemum.

What’s blooming inside: Aptenia, bougainvillea.

Animal sightings: Small robins have been auditioning my trees; two people down the road are letting chickens peck over their gardens.

Weather: Smattering of rain Wednesday night; 12:22 hours of daylight today.

Weekly update: One of the mysteries of spring is what makes plants break ground or leaf out. Lilacs are so tied to temperature scientists use them to measure global warming, while the white spurge always appears around April 4.

I have no idea what influences the Autumn Joy sedum that pushed up new leaves last week. Last year it emerged March 7, while it was April 13 in 2002. It could be temperature, but I don’t know if it’s morning or afternoon, or how many hours of warmth or cold are required, or how much time must pass between the time a temperature requirement is met and emergence.

Georg Arends’ cross between a European Hylotelephium telephium and an Asian Hylotelephium spectabile is a member of the Crassula family that originated in southern Africa where members responded to global drying by altering their photosynthesis technique.

Plants normally use heat form the sun to extract carbon from atmospheric carbon dioxide and excrete the surplus oxygen. The gas exchange occurs through stomatic leaf pores which also allow water to escape when the air is dry. If the soil is too dry to replace the lost moisture, the plant dies.

The Crassulaceae adapted to drought conditions by shutting the stomata in the day, and absorbing carbon dioxide in the night. They store the carbon in malic acid molecules, which turn the leaves bitter. During the day the plants draw on those carbon reserves to support photosynthesis and the leaves return to their normal pH.

With time, the Crassulaceae moved north to the Mediterranean, then east towards Asia where the Hylotelephium diverged. Because the climate there is more temperate, this group of sedums reverted to normal photosynthesis patterns when conditions were good and converted to crassulacean acid metabolism (CAM) when drought was perceived.

The transition between the two metabolic forms is not instantaneous. A British team found telephium could change to CAM metabolism in less than 8 days when plants weren’t watered, while a Chinese group found it took spectabile 15 days to complete the transition.

This time of year, when moisture is abundant, my Autumn Joy is following a normal photosynthetic regime, but when drought appears in early summer the plants will convert to CAM chemical chains of reactions.

They can’t simply go dormant in the heat like spring blooming bulbs, because they don’t begin their reproductive phase until their nascent buds have undergone at least four days with 15 hours of daylight, an event that doesn’t occur until the first of June. Last year the flower buds were visible by the middle of July. While the spring emergence has varied widely, the earliest I’ve noticed flowers is August 12 in 2006, and they appeared around the 23rd the past three years.

Chester Werkman and Harland Wood discovered the chemical mechanics of CAM metabolism in the 1930's when they proved bacteria fixed carbon in a dicarboxylic acid as part of the process of fermentation. After the war, Meirion Thomas measured gas exchanges in Kalanchoë to establish the existence of the temporally separated photosynthesis phases through another dicarboxylic acid in the Crassula family.

Scientists now believe CAM metabolism first appeared in aquatic plants in the Paleozoic era, but was reinvented more than once by terrestrial plants in the late Mesozoic Cretaceous period when the parent group of the Crassulaceae, the Saxifragales, was first appearing.

Many have hoped to show some causal relationship between the Mesozoic atmosphere, which was characterized by high carbon dioxide levels, and CAM metabolism, but so far all they’ve been able to establish is the plants were responding to drought. Autumn Joy may reveal nothing about global warming now or in the summer, but it definitely suggests one way plants adapted to an even greater environmental challenge, the change from water to life on dry land.

Heide, O. M. "Photoperiodic Control of Dormancy in Sedum telephium and Some Other Herbaceous Perennial Plants," Physiologia Plantarum 113:332 - 337:2001.

Keeley, Jon E. and Philip W. Rundel. "Evolution of CAM and C4 Carbon-Concentrating Mechanisms," International Journal of Plant Sciences 164:555-557:2003.

Lee, H. S. J. and H. Griffiths. "Induction and Repression of CAM in Sedum telephium L. in Response to Photoperiod and Water Stress," Journal of Experimental Botany 38. 834-841:1987.

Lin, Zhi-Fang, Chang-Lian Peng, and Gui-Zhu Lin. "Photoxidation in Leaves of Facultative CAM Plant Sedum spectibabile at C3 and CAM Mode," Acta Botanica Sinica 45:301-306:2003.

Mort, Mark E, Douglas E. Soltis, Pamela S. Soltis, Javier Francisco-Ortega and Arnoldo Santos-Guerra. "Phylogenetic Relationships and Evolution of Crassulaceae Inferred from matK Sequence Data," American Journal of Botany 88:76-91:2001.

Thomas, M. "Physiological Studies on Acid Metabolism in Green Plants. I. CO2 Fixation and CO2 Liberaton in Crassulacean Acid Metabolism," New Phytologist 48:390-420:1949

Werkman, C. H. and H. G. Wood. "Heterotrophic Assimilation of Carbon Dioxide," Advances in Enzymology 2:135-182:1942.

Photograph: Week or so old Autumn Joy sedum leaves coming up between old stems, 27 March 2010.

Sunday, March 21, 2010


What’s growing in the area: Iris, grasses.

In my yard: Snow covered everything yesterday.

What’s blooming inside: Aptenia, bougainvillea.

Animal sightings: Rabbit out early after Sunday’s snow, but not yesterday.

Weather: Snow last Sunday took down the power for more than an hour; hail and snow Friday; both storms accompanied by thunder; 12:12 hours of daylight today.

Weekly update: When I was child, my natural world consisted of flowers, trees and grass. I knew there were more primitive plants that had evolved before the earth had dried, but I only knew them as algae, fungus, moss and ferns. Whenever I saw them, they looked alike, and whenever I tried to learn about them, they were too alien to comprehend.

Two weeks ago, when I was walking in the arroyo, I noticed what looked like lumps of dried manure between chamisa bushes in the wide sandy bottom. I didn’t remember them from last summer, but dismissed them as bad memory, poor observation, or some effect of rain and snow. Last Saturday, some had turned green.

I’d been told moss was so fussy about water and shade, it would only grow on the north sides of trees in Michigan, and here it was in the open, in arid New Mexico. And, not just in the arroyo: I saw a large patch among the grasses on the bank and found a little on the west side of my garage.

Actually, what I saw wasn’t just moss, but an entire ecosystem of visible and invisible plants above and below the surface, including types of blue-green algae now called cyanobacteria that permeate the soil to create a protective crust. Moss spores settle into the crevices they create.

During dry periods, the biological crust appears as a darker area on the soil surface. In areas like this, where soils freeze and heave in winter, the ground becomes lumpy, while it remains smooth in warm deserts.

All the components of this biological soil crust adapted to changes when lands rose from the sea and green algae became the nucleus for photosynthetic cells in land plants. Mosses are believed to have developed later, in the Carboniferous age of great swamps and reptiles.

Their cellular structure is still so porous their internal water levels adjust to those of their environment. If the atmosphere dries, moss desicates. If water appears, it rehydrates, repairs any cell damage caused by that change, and resumes active respiration within three minutes.

When a dried moss spore germinates, its first cells are capable of photosynthesis. As the quality of light changes and the hormone auxin appears, the green chrononema cells form different, browner cells that spread out from the colony to absorb nutrients. Once the hormone cytokinin is detected, the caulonema cells produce buds that develop into capsule bearing stems.

The rising buds introduce instability that leads the caulonema cells to compensate with cells that anchor the colony. While the rhizoids don’t absorb or transport nutrients the way true roots do, a team at the John Innes Center found that a gene found in the caulonema and rhizoid cells is the one that controls the development of root hairs in higher plants.

The major difference between mosses and their descendants is that mosses are single chromosome plants that produce two chromosome cells only after the buds have developed. Nature elaborated that two chromosome phase until it became the dominant life form, and the single chromosome appeared only during reproduction.

Those more complex plants solved their dessication problem by developing internal vascular systems that can hold water and move it from roots to photosynthetic leaves. Their pigments helped them cope with evaporation, but they lost the ability to survive severe water loss.

Even now, when the earth’s surface is destroyed by man, by mining or by some natural event like a volcanic eruption or arroyo flood, they aren’t the plants that come back. Instead, it’s the so-called primitive ones that make up the biologic crust I saw, for until they create soil by depositing organic matter and the nitrogen they absorb, there can be no higher form of life.

Belnap, Jayne, Julie Hilty Kaltenecker, Roger Rosentreter, John Williams, Steve Leonard, and David Eldridge. Biological Soil Crusts: Ecology and Management, 2001.

Menand, Benoît, Keke Yi, Stefan Jouannic, Laurent Hoffmann, Eoin Ryan, Paul Linstead, Didier G. Schaefer, and Liam Dolan. "An Ancient Mechanism Controls the Development of Cells with a Rooting Function in Land Plants," Science 316:1477-1480:2007.

Photograph: Moss growing on black soil crust near chamisa in the arroyo, 13 March 2010.

Sunday, March 14, 2010

Juniper Berries

What’s growing in the area: Moss, mushroom, purple aster, young chamisa branches bright lime, June grass, other grasses and seedlings I can’t identify; apple pruning continues.

In my yard: Rose stems have red leaf buds, hyacinths, iris, bouncing Bess, snapdragon, hollyhock, flax, pink evening primrose, black-eyed Susan, Mexican hat.

What’s blooming inside: Aptenia, bougainvillea, Christmas cactus.

Animal sightings: Robin at my uphill neighbor’s, fly in the house.

Weather: Ran Sunday night, snow early Wednesday and Thursday; ground wet and spongy underfoot; 11:52 hours of daylight today.

Weekly update: The edibility of juniper berries differs by species. The European Juniperus communis has been used to season meat and sauerkraut, as well as gin, but our local monosperma is dismissed as unpalatable.

Part of the distaste may arise from false expectations. Juniper berries, despite their name, aren’t fruits but small conifer cones whose fleshy scales merge into an outer skin that holds a resinous liquid. Early in the season, the skin is green like the surrounding leaf scales and the predominate liquid a pinene. Later in the summer, as the seed ripens, the skin turns a purple blue with a waxy gray coating, while the liquid’s chemistry becomes more appetizing.

Our modern reaction is not that of the past. Dan Moerman has found reports that one-seeded juniper berries were cooked or eaten raw by San Ildefonso, Jemez, Cochiti, Hopi and Navajo. Early in the last century, researchers from the Smithsonian were told young Santa Clara men would bring berry-laden branches back to the pueblo to "please their young relations."

Still, William Robbins and John Harrington were told the berries were better when they were "heated in an open pan." The Ramah Navajo and Apache also roasted the berries. At Hay Hollow, an early Mogollon site near Snowflake, Arizona, between the Fort Apache and Navajo reserves, Hugh Cutler identified carbonized juniper seeds in the remains of two houses that date to the time when hunter-gatherers were first settling.

Humans haven’t been the only ones who eat monosperma berries. Townsend’s solitaire, a dusky grey thrush, lives on nothing else in winter, and its seasonal behavior is dictated by that dependence. In the fall of 1973, Michael Salomonson and Russell Balda watched individual birds stake out territories near Flagstaff centered on tall ponderosa pines that allowed the animals to attack intruders in the surrounding juniper.

They noted caged birds ate 204 berries a day, with each berry containing 315.31 calories. From that, they calculated the more active wild birds needed 42,000 cones a season to maintain their energy levels. The number of trees the thrushes protected was far greater than their needs for the winter.

When the men began their observations, the berries were fleshy. The following year was dry, and the junipers produced no new fruit. The ones that had survived the winter shriveled and many fell to the ground. That year the birds returned to their same territories, but needed twice the number of berries to survive.

Mast years, when berries appear in great profusion, depend on the amount of water available from the previous spring when trees are preparing to produce the next year’s cone crop through the following summer when they ripen. However, wet conditions this time of year prevent the pollen from moving from male to female trees.

At the Sevilleta National Wildlife Refuge in Socorro County, where Roman Zlotin and Robert Parmenter watched trees for eight years, the episodic production of berries, usually once every three years, seems related to El Niño oscillations that send more water to New Mexico during the cool phases than during the warm ones.

Somehow Townsend’s solitaires, with their five-year life expectancies, have not only learned how to survive the unpredictable juniper-piñon woodlands in this part of the country when their normal insect diet disappears, but pass that knowledge on to their young even though they exclude them from their winter territories.

Similarly, people who lived in these lands before the Spanish no doubt learned the trees’ cycles, when the berries were most edible, and how to treat them in famine years. It’s only when more reliable foods became available that that specialized knowledge was lost and the berries became inedible to the uninitiated.

Bohrer, Vorsila L. "Paleoecology of the Hay Hollow Site, Arizona," Fieldiana 63:1-29:1972; does not specify the juniper species.

Moerman, Dan. Native American Ethnobotany, 1998.

Robbins, William Wilfred, John Peabody Harrington, and Barbara Friere-Marreco. Ethnobotany of the Tewa Indians, 1916.

Salomonson, Michael G. and Russell P. Balda. "Winter Territoriality of Townsend’s Solitaires (Myadestes townsendi) in a Piñon-Juniper-Ponderosa Pine Ecotone," The Condor 79:148-161:1977.

Zlotin, R.I. and R.R. Parmenter. "Patterns of Mast Production in Pinyon and Juniper Woodlands along a Precipitation Gradient in Central New Mexico (Sevilleta National Wildlife Refuge)," Journal of Arid Environments 72:1562-1572:2008.

Photograph: Last of the one-seeded juniper berries, 6 March 2010; none were left yesterday.

Sunday, March 07, 2010


What’s growing in the area: Russian thistle in low spot, tumble and tansy mustard, stickseed, some grasses

In my yard: First winecup leaf, one sea pink.

What’s blooming inside: Aptenia, bougainvillea, Christmas cactus.

Animal sightings: Rabbit out at daybreak; birds singing when I left for work Thursday.

Weather: Most mornings about 30, yesterday afternoon close to 60; last rain 02/28/09; 11:42 hours of daylight today.

Weekly update: Our local hardware has two mature evergreens for sale, an Austrian Pine and a green spruce. I suspect they’re left over from Christmas, but they could be new arrivals.

One wonders who they think will buy them. Anyone with the heavy equipment necessary to plant them in frozen ground, probably also has the ability to dig up free piñon or juniper bushes he knows will grow here.

Still landscape evergreens have been popular in this country since the wealthy tried to recreate European gardens on their American estates. At The Breakers, completed for Cornelius Vanderbilt II in 1895, Ernest Bowditch used trees to screen the property from neighbors, hedges of Japanese yew and Pfitzer juniper to line the walks, and informal plantings of other evergreens, including arborvitae.

A decade or so later, Vanderbilt’s 13 acre estate had become a model for the next generation of wealth. William Miller suggested those who wanted to copy English gardens should use hedges of Japanese yew in place of the European variety that wouldn’t grow in New England, while those who preferred Italian gardens should substitute arborvitae for the columnar cypresses. By then, Bowditch’s brother James was the primary supplier of Japanese yew.

A few years later, Miller moved to Illinois where farmers were using spirea to hide the high foundations required by coal furnaces. He suggested they substitute Japanese barberry or use native shrubs and vines to "harmonize a house with nature."

While Miller couldn’t convince farmers to replace their spirea, the diffusion of The Breakers aesthetic did spread to middle class suburbs in the 1920's where it merged with the desire for foundation planting. People used tall evergreens at the corners of their houses and near their entrances, and filled the space between with the low growing juniper or yew that then filled the nursery catalogs.

New styles didn’t reach this area until after World War II. The first places built in the village were square, flat-roofed cinder block houses like those found in Los Alamos, with traditional plantings. However, by the middle-1950's, a few had bought land beyond the village and were building low, horizontal homes that used stone façades and low-pitched roofs.

The inbred fear of fire and vermin prevented them from using foundation plantings, but they did use evergreens to mark the front entrance or frame the picture window. Occasionally, someone then or since has planted a low growing evergreen as a specimen in front of one of those ranch houses. With time, they’ve taken on the character of old Japanese shrubs.

Sometime later people planted formal hedges like those of The Breakers along their driveways. Many live in doublewides, but one has a two-story house built in the 1950's or early 1960's. Deciduous shrubs like forsythia and rose of Sharon have been used for hedges at the front road.

More recently, people have returned to the Italian style, with arborvitae used everywhere on property boundaries. In keeping with their European influenced petit McMansions, the white cedar is usually widely spaced to suggest a formal garden, rather than closely planted for privacy.

One lane wandering from the main road towards the river has a mix of the old and new. At the corner, the front yard of a house built between the wars, is filled with tall piñon. Farther back, on the same side, another field has also been planted with piñon and the rest remains vacant.

On the other side of the road, which may have marked the boundary between farms, four newer houses use evergreens as privacy screens. One has 6' shrubs scrambling in front of a stuccoed wall, and two have rows of tightly planted trees.

My favorite place is the one on the corner where a tall English hedge stands between the house and road. At one end, a formal gate with a solid wooden door connects the two areas. The public side was probably once a garden, but now is left to pigweed and áñil del muerta.

On the other side, all I can see is the tall piñon at one end and the shorter pine at the other evoking the frame produced by foundation evergreens. Behind it, one wonders if the same person or same house still exists there, for the Santa Fe adobe revival house has a high stucco wall in front with only the slightest bit of landscaping hidden behind. It’s possible the hedge survives, still carefully pruned, from a house contemporary with the one with piñon across the road.

One reason Miller suggested people should consider using evergreens was "they make a garden beautiful and comfortable in winter," no small feat in this area where drying winds bronze the arborvitae and batter the Japanese honeysuckle. This hedge is always the same, always there, always blue. It’s that illusion of consistency that provides the consolation that this winter, like those past, can be endured.

Bowditch, James. Advertisements for Hiti Nursery in The National Nurseyman, 1909, available on-line.

Bush-Brown, Louise and James Bush-Brown. America’s Garden Book, 1939, on foundation planting and nursery catalogs.

Miller, Wilhelm. "Long-Lived Evergreens for Gardens," The Garden Magazine 15:310-313:1912.

_____. The "Illinois way" of Beautifying the Farm, 1914.

Photograph: Evergreen hedge with piñon at left and pine at right; pigweed and áñil del muerta in front; 7 February 2010.