Oxyria digyna (L.) Hill
 

by Robert Capps, Native Plants of Arizona 2007
Common names: alpine mountainsorrel (1), alpine mountain-sorrel, oxyrie de montagne (2), mountain-sorrel, shan liao (3)
Family: Polygonaceae (2)
Synonomy: Rumex digyna L. (1)
Entymology: Oxyria refers to the acidic taste of the leaves; digyna means two-carpellate, referring to the fruits (4).  

Identification
Growth form: single crown (1)
Roots: thick, fleshy taproot (5)
Stem: 1-4 per plant, 5-50 cm tall, often reddish, simple or branched distally (2)
Leaves: leaf shape reniform, margins undulate (5), glabrous, palmately veined, base cordate, apex rounded; petiole: 1-15 cm (2), 
Inflorescence/flowers: Inflorescence 2-20 cm, peduncle 1-17 cm (2), raceme or panicle (5), inflorescence reddish (1); green inconspicuous flowers (1) 2-6 flowers per ocreate fascicle; perianth 1-2.5 mm (2).  Perianth: four segments, outer two becoming reflexed, and inner two keeled and erect.  Six stamens (5), 1.5-2 mm in length (2).  Two styles (5).
Fruit: achenes, measuring 3-4.5 by 2.5-5 mm, apex notched, two reddish or pinkish veiny wings (2), flat (5).
Similar species: resembles small plants in the genus Rumex (6). 

Ecology
Life history: Herbaceous perennial (5); requires at least 100 frost free days for summer growth (1).
Native/introduced: Native (2).
Photosynthetic pathway:
Phenology: Flowers from June to September, fruits from July through October (2).
Distribution: Circumpolar (5).  Found in early melting snowbeds and areas where snow accumulates, as well as gravelbars, mudflats, scree slopes, crevices, tundra, talus slopes (2), as well as fellfields, ledges, and glacial moraines (5).  In Arizona, Oxyria digyna is found in San Francisco Peaks, from 10,000 to 12,000 feet (6).  Also occurs in Colorado, Wyoming, Montana, Idaho, Utah, Texas, New Mexico, South Dakota, Washington, Oregon, California, Nevada, Alaska and New Hampshire, Greenland, Canada, Europe, and Asia (2). 

Uses
The leaves and stems are traditionally eaten raw, as in a salad, or cooked with seal oil by Alaskan natives (7).  Native people of Greenland sweeten the juice, thicken it with a small amount of rice or potato flour and eat it (8).  Some Native American tribes of the Rocky Mountains ate the leaves in salads (9).  Leaves and stems are forage for caribou, muskoxen and geese, and the rhizomes are eaten by arctic hares and lemmings (10).  Cultivated as an ornamental (3)

References 

1. USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov), 10 December 2007). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

2. eFlora. 2007. Flora of North America: Oxalis corniculata. Retrieved December 10, 2007, from eFloras.org: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200006711

3. USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?26241 (22 September 2007)

4. Gledhill, D. 1989. The Names of Plants. New York: Cambridge University Press.

5. Scott, Richard W. 1995. The Alpine Flora of the Rocky Mountains, Volume 1: The Middle Rockies. Salt Lake City: University of Utah Press.

6. Kearney, Thomas H, Peebles, Robert H. 1951. Arizona Flora. Berkeley: University of California Press.

7. Ager, Thomas A. and Price, Lynn Ager. 1980. Ethnobotany of The Eskimos of Nelson Island, Alaska. Arctic Anthropology. 27:26-48.

8. Porsild, A.E. 1953. Edible Plants of the Arctic. Arctic. 6:15-34.

9. Moerman D.E. 1998. Native American Ethnobotany. Portland: Timber Press.

10. Porsild, A. E. 1957. Illustrated flora of the Canadian Arctic Archipelago. Natl. Mus. Can. Bull. No. 146.