Oxalis

What’s blooming in the area: Apricots, a few crabapples, one pink hyacinth, mossy phlox, hoary cress; tansy, tumble and purple mustard; native and common dandelion; Siberian elm in bud, arborvitae, piñon, and snakeweed greening. The truck garden was plowed early in the week, and weeds along the banks burned yesterday; so many people have been burning, the smell of smoke was strong Tuesday morning.
What’s blooming in my yard: Forsythia and oxalis; peach buds pink; first tulips, daffodils, daylilies, sweet peas, garlic chives, Maltese cross, Jupiter’s beard, tansy, and fern-leaf yarrow emerged; globe willow put out first leaves
What’s blooming inside: Bougainvillea, aptenia, kalanchoë; rochea few flowers.
Animal sightings: First ant hills, bird standing guard on the utility pole in morning, cabbage butterfly last Sunday.
Weather: Frost Monday and Tuesday; mornings later in week around 40, and afternoons rose to near 70; last rain 3/13/09; 12:16 hours of daylight.
Weekly update: The first flowers of spring are often weeds: dandelions, tansy mustard, the Oxalis that poked out last Sunday near my back porch. Usually domesticated plants wait until conditions stabilize, but this year’s early warmth fooled the five-petaled yellow perennial.
Wood sorrels are particularly sensitive to heat: I don’t usually see their quarter-inch flowers until the first of May, when they retire by midday. Scientists aren’t sure if the plants respond more to light, heat, or internal circadian rhythms, but anyone who has one knows the alternating sets of three leaves fold into pyramids at night, on cloudy days, when temperatures rise, and when they’re touched.
The little Oxalis began as a native wildflower that moved into greenhouses where its shamrock leaves spread along earthen floors. When its flat brown seeds settle in small pots used for perennials like purple coneflower, it shoulders aside the seedlings in its quest for food, water, and light. However, when it appears in larger containers with shrub cuttings like azaleas, it has little affect on the health of its host.
Today the plant is ubiquitous, but it’s provenance is obscure because botanists have used small differences to define discrete species, then applied the same terms for different variants, and now are grouping them all into a single class. Today only the more aggressive creeping rhizome, Oxalis corniculata, is separated from my stricta which starts out erect, then flops from the point where its branches emerge from the main stem. The reason the distinction survives may arise less from biology than the fact the first is seen as more difficult to eradicate in cool nurseries.
When I see people identify an Oxalis, I’m more sure of their personal experience than I am reality. I know John Josselyn saw a yellow wood sorrel in New England in the 1670’s, but I don’t know if Edward Tuckerman is correct to identify it as the creeping species. I’m sure the Cherokee use wood sorrel for a variety of purposes, but don’t know who is correct, Paul Hamel and Mary Chiltoskey, who suggest they use corniculata, or Myra Jean Perry who thinks they use my plant.
The differences don’t seem to matter much: people have substituted one species for another without serious consequences. Plains tribes use both the purple-flowered violacea and my yellow one as food for their children and horses. In Poland after World War II, children who ate the local white-petaled acetosella would eat the alien stricta when it appeared.
John Gerard used the local acetosella in a sauce to treat stomach problems in sixteenth century England, while Nicholas Culpepper recommended boiling the leaves into a red syrup for blood and ulcer problems in the mid 1650's. In this country, the Santa Clara chewed roots of the purple-flowered species for diarrhea, while San Ildefonso chewed the leaves to treat sores and swellings. Nearby Spanish-speakers boiled the leaves to expel worms.
By the end of the nineteenth century, King's American Dispensatory suggested both stricta and violacea were acceptable substitutes for the European acetosella, and found them useful against scurvy. However, every writer warns against overuse. The ascorbic acid converts into oxalic acid, which can bond with calcium in the body to produce kidney stones.
I think my Oxalis is a stricta that arrived from Iowa with a field-grown raspberry. I spotted the leaves in 2001 and 2003, and have seen the flowers every year since 2007 in the same place. In friendlier climes, it pollinates itself and the narrow green pods expel seed, sometimes spreading into a nuisance. Here I think a single yellow wood sorrel root has managed to survive in the drip line as one of the more benign signs of spring, one that blooms fitfully season after season without producing scratches or rashes.
Notes:Culpeper, Nicholas. Culpeper’s Complete Herbal and English Physician, 1650's; 1826 edition republished in 1981.Curtin, Leonora Scott Muse. Healing Herbs of the Upper Rio Grande, 1947, republished 1997, with revisions by Michael Moore.Felter, Harvey Wickes and John Uri Lloyd. King's American Dispensatory, 1898, Henriette Kress’s copy available online.Gerard, John. Gerard’s Herball, 1597; reprinted as Leaves from Gerard’s Herball, 1969, from a 1929 edition by Marcus Woodward.Josselyn, John. New England’s Rarities Discovered in Birds, Beasts, Fishes, Serpents and Plants of That Country, 1672, reprinted by University of Michigan, University Library with 1865 notes by Edward Tuckerman.Luczaj, Lukasz. "Archival Data on Wild Food Plants Used in Poland in 1948," Journal of Ethnobiology and Ethnomedicine 4:4:2008.Moerman, Dan. Native American Ethnobotany, 1998, and on-line database, includes Melvin R. Gilmore, Uses of Plants by the Indians of the Missouri River Region, 1919; Paul B. Hamel and Mary U. Chiltoskey, Cherokee Plants and Their Uses -- A 400 Year History, 1975; and Myra Jean Perry, Food Use of "Wild" Plants by Cherokee Indians, 1975.Robbins, William Wilfred, John Peabody Harrington, and Barbara Friere-Marreco, Ethnobotany of the Tewa Indians, 1916.
Photograph: Yellow Oxalis flower, 15 March 2009.