Sunday, January 31, 2010

Miniature Pomegranate

What’s still green: Arborvitae, juniper and other evergreens, Apache plume, some rose stems, cholla, prickly pear, yuccas, Japanese honeysuckle, grape hyacinth, sweet peas, vinca, beardtongues, coral bells, sea pink, pink and yellow evening primroses, snapdragons, chrysanthemums, purple aster, cheat grass.

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

What’s red: Saint John’s wort.

What’s yellow: Weeping willow branches.

What’s blooming inside: Bougainvillea and aptenia; rochea and Christmas cactus leaves tinged with red.

Animal sightings: Rabbit and smaller animal tracks in snow Friday morning.

Weather: Rain early Thursday, snow later in day with even deeper mud between; ice everywhere Friday morning; 10:28 hours of daylight today.

Weekly update: A woman I work with knows I like plants, and so occasionally shows up with some improbably bright colored one for the office. It’s often some type of campanula or orchid, but for my birthday two years ago it was a miniature pomegranate.

The 6" high tree continued putting out tiny, trumpet-shaped claret flowers until Christmas. When I brought it home for the week we were closed, it went into a a sulk. The brown branches started dropping their narrow oval leaves when it went back to the office, and there were never any new ones.

This past Thanksgiving I brought it home again, took what turned out to be three plants from a 3" pot, stuck them in existing pots on the enclosed porch and left the deciduous trees to adapt. They dropped whatever leaves remained.

Last weekend I discovered new leaves at the bases of the spreading branches. Sun angles had changed, morning temperatures had stabilized around 20, and, outside, some chrysanthemums, snapdragons and the yellow alyssum had put out new growth.

While it was still blooming in Santa Fe, a neighbor woman noticed it. When I mentioned what it was, she said she knew. Each time Olga came by, she looked at the plant, sometimes saying she wished she had one. I would have given her mine, knowing she could have nursed it back to health, except Gini, the woman who gave it to me, was keeping an eye on the ripening single fruit.

I never knew where Olga was from, but I think some part of México, maybe Zacatecas like so many in the neighborhood. At the time I thought she was attracted to the flowers like we were. Now I think it had the same nostalgic value for her that hollyhocks have for so many of us, a reminder of something from her childhood.

Pomegranates are an evolutionary dead end thought to be native to the Iranian plateau and its surrounding mountains. The only other Punica species is found on Socotra Island, off the horn of Africa in the Indian Ocean. Phoenician traders disbursed the plant. It moved to Rome from their Carthaginian colony in modern Lybia, and was taken to Spain by the Moors where some ten varieties were growing when Ibn al-Awam was writing in the late 1100's.

William Dunmire says that after Hernán Cortés subdued the Aztecs in 1521, the Spanish divided the Cuernavaca valley in modern Morales state into large estates to produce its food. By 1530, the orchards there included pomegranates.

Then, in 1531, Dunmire says, the Spanish settled Puebla in the Tehuacán Valley on the route to their main port at Veracruz. Administrators created smaller land allotments for people who failed to grow sugar in the Caribbean and were moving to the mainland. Toribio Motolinía, who wrote between 1536 and 154, said that there "fruit trees of every kind prosper extremely well, especially pomegranates."

Granadas may have been brought to México for food or medicine or the tannins in their rinds that were used to cure leather. The hard wood was used to construct one of the early buildings on the Pánuco river nearer Veracruz where Cortés had defeated the local inhabitants in 1523.

Whatever utilitarian purposes they served, pomegranates were quickly used for decoration. In 1652, Thomas Gage mentioned the trees were growing in the gardens of the elite in Mexico City.

When Maturin Ballou was visiting Zacatecas, the mining center that was home to Cortés son-in-law, Juan de Oñate, and many of the early settlers in the Española valley, he noticed that while the poor lived in adobe hovels in the late 1880's, he would occasionally see "a small garden inclosed with high adobe wall, belonging to some rich mine owner, in which the tall pomegranate, full of scarlet bloom, or a stately pepper tree, dominates a score of others of semi-tropical growth."

Some thirty years later botanist Joseph Kirkwood visited Hacienda de Cedros on a desert plateau north of the city. He remembered that when he came near a hamlet built around a spring at the base of some surrounding slope, he would find "ash and pepper trees, pecans, avocados, figs, pomegranates, apples and grapes, rows of magueys and hedges of tuna-bearing nopáls."

In Zacatecas estado, like elsewhere the Spanish settled, the red fruited tree moved beyond the courtyards of the aristocracy and put down roots wherever conditions were favorable. Nasif Nahle Sabag still curses the "ignorant mayor" who cut down the pomegranate that grew in the plaza of his childhood village in Zacatecas along with eucalyptuses and an apricot. Olga could recognize a tiny plant from more than six feet.

Today, pomegranates grow wild in Azerbaijan and are still hybridizing and mutating. Gregory Levin saw dwarfs, creepers and densely branched bushes around Kopet Dag in the 1930's, and found the external characteristics of full-sized trees to be quite variable. He theorized the changes there, and in other places where Punica granatum had developed local variants, were caused by human selection and high background radiation.

A dwarf plant was sent from the Caribbean to Philip Miller at the Chelsea Physic Garden, who described it in 1754. He believed it was cultivated for "the Beauty of its Flowers," which appeared most of the year on shrubs that rarely grew more than three feet. The fruit on his tree was the size of a walnut and "not very pleasant to the Taste."

Miniature pomegranates, called Nana by botanists, remain highly variable. Brent and Susie Walstron say they only offer cloned varieties to bonsai growers because "many plants sold are actually seedlings of dwarf plants that are quite variable, some of them even nearly full size."

The plant that attracted Gini and Olga is probably one of those Nana bastards distributed by the Nurserymen’s Exchange of California. But predictable habits mean nada compared to Gini’s fascination with miniaturization and Olga’s childhood memories.

Ballou, Maturin Murray. Aztec Land, 1890.

Dunmire, William W. Gardens of New Spain, 2004, quotes Toribio Motolinía and Thomas Gage.

Kirkwood, J. E. "Desert Scenes in Zacatecas," Popular Science, November 1909.

Levin, Gregory Moiseyevich. Pomegranate Roads: A Soviet Botanist's Exile from Eden, 2006,
translated by Margaret Hopstein; quotes Ibn al-Awam

Miller, Philip. The Gardeners Dictionary, volume 3, 1754.

Sabag, Nasif Nahle. "Nieves, Zacatecas," 2004, on Biology Cabinet Organization website.

Walston, Brent and Susie. "Pomegranate" on Evergreen Gardenworks website.

Photograph: Miniature pomegranate with chaste tree, 30 January 2009.

Sunday, January 24, 2010

Arroyo Walls

What’s still green: Arborvitae, juniper and other evergreens, Apache plume, some rose stems, cholla, prickly pear, yuccas, Japanese honeysuckle, grape hyacinth, sweet peas, vinca, beardtongues, coral bells, sea pink, pink and yellow evening primroses, purple aster, cheat grass; new chrysanthemum and snapdragon leaves.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, saltbush, winterfat; new yellow alyssum leaves.

What’s red: Saint John’s wort.

What’s yellow: Weeping willow branches.

What’s blooming inside: Bougainvillea and aptenia; rochea and Christmas cactus leaves tinged with red; new leaves on pomegranate and zonal geraniums.

Animal sightings: Rabbit out early Wednesday between storms. Horses down the road were unhappy with water in their paddock Friday morning: they had walked to the edge of the flooded land and were just staring when I drove by.

Weather: Warm temperatures brought more rain than snow this week, and 3" of mud on frozen ground in the drive; ice now fills many terraced beds in early morning; 10:10 hours of daylight today.

Weekly update: Architects rarely get on with the men tasked with building their designs, because too many architects lack enough training in structural engineering and the practical problems of routine work like running conduit and pouring concrete.

Gardeners can have the same problems. When Louise Beebe Wilder said she filled the joints of her stone steps "with inviting sandy loam in the hope of attracting some little green home-seeker" one wonders how long before those steps needed repair from root damage.

Similarly, when Gertrud Jekyll said the walls defining a sunken garden were built with "blocks of stone with wide joints, all laid a little sloping back, so that the whole face of the two walls lies back." and that "the wall was planted, both as it was built, and also afterwards," one wonders if she’d ever observed the damage caused by water falling back into a wall in summer or freezing under it in winter.

The men repairing the near arroyo are all too aware of the dangers of water. Near the road, on the downriver side, a pipe empties water coming through the ditches that wasn’t diverted for irrigation. That part of the arroyo is nearly twice as deep as it is on the other side of the road, and I rather suspect threatens the integrity of the road itself. I hate meeting trucks there because we’re both hugging the center.

Last summer, a new acequia outlet was installed on the upriver side that threatens the bank there. Although storm water rarely does more than wet a narrow bottom channel, an afternoon storm several years ago sent water rushing through that part of the arroyo. When I passed, the owner was out taking pictures. Soon after he offered his property for sale.

By definition, arroyo banks are soft. When water slides over the slopes leading to the river, it washes away unprotected layers between plants. Water continues to channel into the softer rivulets, washing away more dirt and gravel until a full arroyo or its feeder forms. Those walls, even if sandstone, can then be carved away by both wind and rain.

Last summer, men began stabilizing the near arroyo walls. On the upriver side, they abraded the bank to make a smooth incline, then covered it with black fabric to prevent water and seeds from getting to the soil. As if they were getting ready to stucco the bank, they next laid out two layers of mesh that resembled chicken wire, but was heavier gauge, and drove in anchoring steel angle posts.

Finally, they took large rocks, and dumped them between the layers. On the other side, the banks were so steep they needed to be terraced. There they formed stepped back rows of caged rocks.

Work on the downriver side was finished and the face of the culverts carrying water under the road was cemented over before winter. Work on the other side stopped, apparently awaiting the arrival of more 8' culverts. This week, the remaining snow, after days of rain and light snow, marked the path of water and potential destruction.

Wilder was concerned that "where time is slow to bestow its softening touch of moss and lichen, stonework in the garden is apt to have an alien, unconnected look" and believed "encouraging suitable plant life in the chinks and joints" would create "a more harmonious ensemble."

Penelope Hobhouse suggests Jekyll was concerned with the needs of terracing sloping sites, and emphasizes she said "nothing is prettier or pleasanter than all the various ways of walling, that is to say, rough wall-building without mortar, especially where a suitable kind of stone can be had locally."

Here cost, availability and function dictate the use of what we call large river rock. The rocks long ago fell from mountains to the north and have been smoothed by time. Many are granite or other hard stone, not erodible sandstone or limestone. Eventually the wire net will oxidize to the same monotonous grey. Even though the rocks may be somewhat indigenous, the treated arroyo walls will remain the alien, but necessary presences disdained by Wilder and Jekyll. However, I’d rather drive a road over a reinforced arroyo than one that’s picturesque and crumbling.

Hobhouse, Penelope. Gertrude Jekyll on Gardening, 1983, compilation of writings by Jekyll with commentary by Hobhouse.

Jekyll, Gertrude. Wall and Water Gardens, 1901.

Wilder, Louise Beebe. Colour in My Garden, 1918, emphasis in original.

Photograph: Arroyo wall after night of rain, 22 January 2010; soft bank and local gravel are in the right foreground, the interrupted repairs to the left; the road is directly to the right.

Sunday, January 17, 2010

Shasta Daisy

What’s still green: Arborvitae, juniper and other evergreens, Apache plume, some rose stems, cholla, prickly pear, yuccas, Japanese honeysuckle, vinca, beardtongues, coral bells, sea pink; snow still covers grape hyacinth, pink and yellow evening primroses, purple aster, cheat grass, bases of needle and June grasses.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, saltbush, winterfat.

What’s yellow: Weeping willow branches.

What’s blooming inside: Bougainvillea and aptenia; rochea and Christmas cactus leaves tinged with red.

Animal sightings: The birds that land in the peach don’t chirp or sing; they make clacking noises that sound like two sticks hitting one another.

Weather: Early morning temperature still dropping to mid-teens, but afternoons warming enough to thaw parts of the drive; last snow 12/30/09; 9:50 hours of daylight today.

Weekly update: Gardeners usually know what they do and why they do it. When they look at the consequences, they’re never sure exactly what happened. Nature has a way of intervening.

I wanted tall white flowers along the west side of the garage and so ordered six Shasta daisy seedlings in 1998 that didn’t survive. I planted six Alaska cultivars in 1999 and added six Exhibitions in 2000. Each started to bloom the following summer, until the grasshoppers found them. By 2003 they appeared to have died out, but one came back the next spring.

Every year since the cycle has been repeated. The one Alaska plant comes up; the grasshoppers eat the flowers before they fully open on stalks that never get more than 6" high. With this year’s atypical weather, the leaves were able to come back in the fall and even started to put out new growth before the snows of December finally collapsed the older leaves.

Luther Burbank knew what he wanted when he bred the Shasta daisy, a daisy that "would be the purest imaginable white in color" And he knew exactly what he did to create that whiteness.

He began growing ox-eye daisies in California and selected the best plants to fertilize with pollen from a Pyrenees flower, Leucanthemum maximum. The result had the grace of the maternal Leucanthemum vulgare, but the large flowers of the father. Still he thought them a bit dingy.

Next he tried adding the pollen from a Portugese daisy he ordered from Germany, Leucanthemum lacustre, but the improvement was minor. Then he tried the pollen from the Japanese Nipponanthemum nipponicum and produced a whiter, larger flower, but lost the leafless stalk he desired. He continued selecting the best of its offspring, until he got the "Shasta hybrids" he sold in 1901 and the Alaska he released in 1904.

What he didn’t know is how it all happened. He’d been inspired by Charles Darwin’s Variation of Animals and Plants under Domestication and was systematically applying the concept of natural selection with the methods then in use, controlling the pollination between two plants. He began by improving the fruits of members of the rose family like plums and blackberries.

When he began on daisies, all the perennials he used were considered members of the Chrysanthemum genus that had already been much improved. In the 1990's, taxonomists tried to rationalize the composite family into new genuses grouped within tribes and subtribes. They separated the Leucanthemums into what they believed was a monophyletic genus, meaning one that evolved from a common ancestor in Europe, possibly the Mediterranean area. The Japanese plant was redefined as a Nipponanthemum which was "provisionally placed as an aberrant member of subtribe Leucantheminae."

Tyge Böcher and Kai Larsen believe those Leucanthemum species that grow in England and Atlantic Europe tend to have the usual two sets of chromosomes, while those living elsewhere on the continent and in the southern mountains have many more. In fact, the widely distributed vulgare can vary from two to ten chromosomes, while maximum has ten and lacustre has 22. The Japanese plant has the usual two.

Botanists have found no universal rule governing the ability of closely related species to interbreed, but have found the greater the number of chromosome sets, the greater the possible variations, and often the greater the size of the plant, fruit or flowers.

Burbank couldn’t have known this in 1901 when he released Shasta daisies. In 1872, Edmund Russow had observed some rod shaped entities in cells during early mitosis just after the male and female cells had merged that subsequently change shape and then couldn’t be seen with an optical microscope. It wasn’t until Walther Flemming found a way to stain the cells with an aniline dye that chromosomes could be seen easily, but no one understood the significance of what they were seeing until the work of Gregor Mendel was publicized in 1900.

However, by the time Burbank described how he produced the Shasta daisy in 1914 he was aware, at least in general, of Mendel’s work. The 65-year-old man remembered "thousands of seedlings were raised each year for five or six ensuing seasons," the number of generations required by Mendel to assure a given trait will always appear. Without knowing the numbers of chromosomes, he also knew the possible permutations required he plant many more than four seeds.

None of his comments or intentions, of course, have anything to do with why Shasta daisies grow in a massed bed down the road, don’t survive three years for my next door neighbor, and behave like displaced persons in the icy drip line on the west side of my garage. The genes that make the taproot prefer heavy soil or require cold winter temperatures to bloom were outside his interest, but they are the natural forces that ultimately determine if Leucanthemum superbum can grow in this part of northern New Mexico.

Böcher, Tyge W. and Kai Larsen. "Cytotaxonomical Studies in the Chrysanthemum Leucanthemum Complex," Watsonia 4:11-16:1958.

Bremer, Kare and Christopher John Humphries. "Generic Monograph of Asteraceae-Anthemideae," The Natural History Museum Bulletin 23:71-177 :1993.

Burbank, Luther, John Whitson, Robert John, and Henry Smith Williams. Luther Burbank: His Methods and Discoveries and Their Practical Application, volume 2, 1914; chapter 1 reprinted as Luther Burbank, The Shasta Daisy: How a Troublesome Weed Was Remade Into a Beautiful Flower, by Athena University Press, 2004.

Darwin, Charles. The Variation of Animals and Plants under Domestication, 1868, revised 1875.

Heide, O. M. "Dual Induction Control of Flowering in Leucanthemum vulgare," Physiologia Plantarum 95:159-165:1995.

Strother, John L. Chromosome counts from entries on Leucanthemum and Nipponanthemum on eFloras’ Flora of North America website.

Photograph: Shasta daisy "Alaska," 10 January 2010.

Sunday, January 10, 2010

Prickly Lettuce

What’s still green: Arborvitae, juniper and other evergreens, Apache plume, some rose stems, cholla, prickly pear, yuccas, Japanese honeysuckle, vinca, beardtongues, coral bells, sea pink; snow still covers grape hyacinth, pink and yellow evening primroses, purple aster, cheat grass, bases of needle and June grasses.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, saltbush, winterfat.

What’s yellow: Weeping willow branches.

What’s blooming inside: Bougainvillea and aptenia; rochea and Christmas cactus leaves tinged with red.

Animal sightings: Birds nesting in my porch ceiling.

Weather: Morning temperatures ranged between 14 and 24, until falling to 8 again this weekend; last snow 12/30/09

Weekly update: Seed and nursery catalogs are still arriving, and with them the hopes of summer. As dreams should be, not all are practical. Every now and then I indulge in fantasies of the impossible for northern New Mexico, like a fern garden under my porch.

It’s an occupational hazard with gardeners. Even Linnaeus had his chimera, a garden laid out like a clock, with plants in each section that opened at that hour. He considered goat’s beard for 4 am, sow thistles, dandelions and bindweed for 5 am, hawkweeds for 6 am, and common lettuce for 7 am.

When I look at that list, I’m struck by the paucity of ornamental plants available in 1751. Man’s relationship with plants had gone through few phases then, and all had been related to getting enough to eat. The importations of brilliant colored, large flowers that stay open all day, every day of the summer was yet to come.

Humankind had begun by gathering seeds to eat, and somehow making the great discoveries of protecting desirable plants and saving seeds. There’s no such thing as garden lettuce, Lactuca sativa, found in the wild. Geneticists have found it nearly identical with the prickly lettuce that Eviatar Nevo’s team believes evolved in eastern Turkey and Armenia in response to "high abiotic and biotic stresses" in that region.

Nothing about Lactuca serriola would lead you to protect or eat it. The leaves and stems are thorny, the leaves are bitter, the stem is filled with a milky sap that stains the hands, and the small washed out yellow flowers are dwarfed by their tall stalks. The composites not only stay open only a few hours, but droop. It’s only now that the stalks have stiffened that they stand completely upright.

We know Egyptians began domesticating the plant from tomb paintings dating back 4500 years. Louis Keimer has shown the evolution of the art work, and possibly the plant in that art. By the time of Senusret I (1971-1926 bc), it was pictured with Min, the god of fertility, which leads some to believe it was used as an aphrodisiac. Others are more prosaic, arguing it was grown for the seed oil, much as K. Lindqvist found primitive sativa plants being used in the 1950's.

Herodotus repeats a story about the Persians, that in its Egyptian version, suggests lettuce had moved to their tables by the mid-500's bc. Edward Sturtevant found references to it by Hippocrates (430 bc) and Aristotle (356 bc). Soon after the death of Christ, Pliny the Elder described it as a soporific that controls the appetites, aids digestion and purges the stomach. It’s thought that people then were selecting plants that had higher amounts of lactucarium, a chemical that was still in the United States Pharmacopoeia in 1898 as a sedative.

The Spanish were growing lettuce by the time Columbus packed seeds in 1493 along with 1,200 settlers, horses, cattle, sheep, and wheat onto 17 ships to found a colony on Hispañola. When Gaspar Pérez de Villagrá traveled with Juan de Oñate to the Española valley in 1598, he suggested that "after we have dealt with them," Santa Domingo will "harvest the red wheat and garden stuff, such as lettuce and cabbage." By 1601, one of the colonists wrote they indeed were irrigating lettuce from the Chama river where they had taken land from the San Juan. In 1931, Isleta was still using it like the Romans for stomach aches.

The next phase of the European relationship with plants began when Spanish ships returned with the potatoes, tomatoes, and corn that revolutionized peasant diets. They joined the sugar, coffee and tea coming from the east that displaced the first spices, the mace that flavors Swedish meatballs and the cloves used with baked ham. Both were combined with the new pumpkins.

Lettuce remained a small part of the diet, until selective breeding programs increased the edibility of the leaves. Atlee Burpee introduced the firm headed ice burg lettuce in 1894, that could be shipped by train to the tables of New York society in winter. From there it spread into the American diet as a food and not a medicine.

Ohio State says its prickly lettuce ancestor was recorded in this country around 1860, and by 1915, Elmer Wooten and Paul Standley say it had "become a troublesome weed in some of the river valleys of New Mexico," especially around Farmington, Ruidoso and the Mesilla valley.

The phase of indulging oneself with ornamental plants only came with improved standards of living and tropical plants in the nineteen century. Linnaeus may never have created his horologium florae, but his vision was revived by gardeners who created carpet beds that looked like clock faces with one flower for the background, and another for the numbers. Some even buried clock works so the hour and minute hands could turn over the flowers.

Now, I suppose, one could make such a carpet bed with various shades of lettuce advertised in the newly arrived catalogs. Then, one could leave one stalk of prickly lettuce in the center to act as the style of an edible sundial. The dead prickly lettuce stalk that hid in the rugosa rose now casts its shadow every day.

Notes:Deagan, Kathleen A. and José María Cruxent. Columbus's Outpost among the Taínos: Spain and America at La Isabela, 1493-1498, 2002, draws on the document collection published by Juan Gil and Consuelo Varela, In Temas Columbinas, 1984.

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

Harlan, Jack R. "Lettuce and the Sycomore: Sex and Romance in Ancient Egypt," Economic Botany 40:4-15:1986; Mark Andrews, "The White Chapel of Senusret I," includes a reproduction of the most famous of the Egyptian paintings of lettuce and Min.

Herodotus. The Persian Wars, translated by: George Rawlinson 1942, and edited by: Bruce J. Butterfield.

Jones, Volney H. The Ethnobotany of the Isleta Indians, 1931, cited by Dan Moerman, Native American Ethnobotany, 1998.

Keimer, L. Die Gartenpflanzen im Alten Ägypten, 1924, drawings reproduced in "Lettuce (Asteraceae; Lactuca spp.)" by A. Lebeda, E. J. Ryder, R. Grube, I. Doleñalová, and E. Krístková in Ram J. Singh, Genetic Resources, Chromosome Engineering, and Crop Improvement: Vegetable Crops, volume 3, 2006.

Lindqvist, K. Studies in Wild and Cultivated Lettuce, 1960, dates it to 4500.

Linnaeus. Philosophia Botanica, 1751; list of his plants taken from Wikipedia entry on "Linnaeus’ Flower Clock."

Nevo, Eviatar Nevo, Richard Michelmore, null Hanhui Kuang, Herman J. Van Eck, Delphme Sicard "Evolution and Genetic Population Structure of Prickly Lettuce (Lactuca serriola) and Its RGC2," Genetics 178:1547-1558:2008.

Ohio State University, "Prickly Lettuce" in its on-line Weed Guide.

Pliny the Elder. Natural History: A Selection, translated by John F. Healy, 1991.

Sturtevant, Edward Lewis. Sturtevant’s Edible Plants of the World, edited by U. P. Hedrick, 1919, reprinted by Dover Publications, 1972.

Villagrá, Gaspar Pérez de. Historia de la Nueva México, 1610, translated and edited by Miguel Encinias, Alfred Rodrígue and Joseph P. Sánchez, 1992.

Wooten, Elmer Otis and Paul Carpenter Standley. Flora of New Mexico, 1915, as scariola integrata.

Photograph: Prickly Lettuce, 3 January 2010.

Sunday, January 03, 2010


What’s still green: Arborvitae, juniper and other evergreens, Apache plume, fewer rose stems, cholla, prickly pear, yuccas, Japanese honeysuckle; snow still covers grape hyacinth, St. John’s wort, vinca, beardtongues, coral bells, rock rose, sea pink, pink and yellow evening primroses, purple aster, cheat grass, bases of needle and June grasses.

What’s grey, blue-grey or grey-green: Piñon, pinks, snow-in-summer, saltbush, winterfat.

What’s yellow: Weeping willow branches.

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

Animal sightings: Rabbit in drive.

Weather: Veneer of new snow when I awoke Thursday morning.

Weekly update: The best thing about snow-in-summer is that the grey leaves are always there. Even now, after being dumped with snow, the hairy stems and narrow leaves are there.

Of course, that wasn’t always true. The seedlings I repeatedly bought from a Santa Fe nursery were root bound with a film between the rootballs and plastic containers. They never survived. Finally, in 2006, cheaper plants arrived in the local hardware and they’re the ones that took hold in my windswept island bed with pinks and coral bells.

And of course, they didn’t always exist. However, the Cerastium genus has been around longer than Europe and Asia or North and South America have been joined. Back during the Miocene, 5.1 to 24.6 million years ago, the seas were receding and grasses were dominant. Members of the genus crossed the Bearing land bridge in the same general period grazing mammals moved across.

Today, Cerastium tomentosum lives in the central and southern Apennines of Italy, which themselves didn’t exist until the African plate collided with the peninsula in the Miocene and pushed up the limestone seabed. The five-petaled white flowers can be seen blooming in spring around Pescasseroli in the Abruzzi National Park and are found in the Giardino Botanico Daniela Brescia in the more rugged Majella National Park to the north.

Whether these plants are the relics of some earlier species with a wider distribution isn’t known. What has confounded botanists is that plants with very similar, but slightly different characteristics, have been found from Spain to the Balkans and Caucasus, while at least six closely related, separate species have been identified in Italy.

These members of the carnation family weren’t always considered a desirable garden flower. William Robinson published a suggestion in 1876 that the plants provided a suitable contrast to purple and crimson flowers and thought they could be used to “good effect in the wild garden” in 1903, but dismissed them as “edgings” in his more influential English Flower Garden.

Gertrude Jekyll seems to be the first to wax enthusiastic about their ability to grow in walls where their rhizomatous roots could seek cool water in the crevices. As she observed in 1901, any number of plants can live on flat land, but their “way of growing in hanging sheets is in itself a very interesting characteristic, pointing to the use of many beautiful things in circumstances that could not otherwise be dealt with so satisfactorily.”

By 1916, American Louise Beebe Wilder was covering her autumn crocuses with a “gray blanket of Cerastium” and two years later described stone steps nearly covered by a mat that began as “a frail thread of life in the top joint, has gradually felt its way, tumbling over the treads and running its green fingers along the transverse joints and on, until the hard lines of the steps are quite lost beneath the soft gray covering that does not suffer in the least from being walked upon.”

The tomentosum subspecies that’s been used in gardens is as variable and adaptable as its wild cousins. The species that spread through the arctic sometime during recent geologic time appears in forms with 8 or 12 sets of chromosomes and crossbreeds with the tetraploid Cerastium arvense.

When snow-in-summer finally began to be widely planted in England, it escaped and, by 1960, was wild everywhere on the island. Most specimens are octoploids (2n=72) that also cross themselves with arvense. On this continent, they’ve naturalized in a narrow belt from Nebraska west. The perennial is more common from Wisconsin east to the Atlantic and up into eastern Canada, where it also has 8 sets of chromosomes and hybridizes with an introduced arvense subspecies.

It’s true the plant can adapt to a wide variety of conditions, including roof gardens, but it’s also apparent to botanists that its method of adaptation is not the usual one of natural selection and potentially decreasing biodiversity. Instead, Cerastium has kept an open definition from its Miocene days of its genetic structure which allows its species to exist by expanding, not limiting, their genomes.

Brysting, Anne K, Bengt Oxelman, Katharina T. Huber, Vincent Moulton and Christian Brochmann. “Untangling Complex Histories of Genome Mergings in High Polyploids,” Systematic Biology 56:467-476:2007.

Jekyll, Gertrude. Wall and Water Gardens, 1901.

Khalaf, M. K. and C. A. Stace. “The Distinction between Cerastium tomentosum L. and C. biebersteinii DC. (Caryophyllaceae), and Their Occurrence in the Wild in Britain,” Watsonia 23:481-491:2001.

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_____. The Garden, anonymous article, “Effective Mixed Flower Beds,” 1876.

_____. The Wild Garden, 1903.

Scheen, Anne-Cathrine, Christian Brochmann, Anne K. Brysting, Reidar Elven, Ashley Morris, Douglas E. Soltis, Pamela S. Soltis and Victor A. Albert. “Northern Hemisphere Biogeography of Cerastium (Caryophyllaceae): Insights from Phylogenetic Analysis of Noncoding Plastidnucleotide Sequences,” American Journal of Botany 91:943-952:2004.

Wilder, Louise Beebe. Colour in My Garden, 1918.

_____. My Garden, 1916.

Photograph: Snow-in-summer under a glaze of snow, 31 December 2009; taller leaves and akimbo branches are cheddar pinks.