Leaf:  Alternate, palmately compound with 3 leaflets, clover-like; each leaflet nearly heart-shaped with an apical notch, nearly folded in half  along midrib, 1 to 2.5 cm long, 1.5 to 3 cm wide; smooth on the edges; upper surface dark green, smooth to kind of fuzzy; lower surface lighter green and more fuzzy than the top; leaf stalk slender, about 2.5 cm long; leaves may be tinted with some purple. 

Flower:  In small bunches, each flower on a slender stalk, some drooping; blooming April to October; each flower 6 to 10 mm long, with 5 yellow, oblong petals, 5 sepals, 10 stamens.

Fruit:  Elongate seed pod, capsule cylindrical and sharp-beaked (pointed), flat sided with 5 ridges, sparsely hairy or without hair; 5 to 20 mm long; pods on long pedicels that are commonly bent; green, matching their leaves; seeds ovate to elliptic, 1 to 1.3 mm long, flattened, orange-brown; ripe seed pods shooting the seed from the plant when touched, sending seed up to 4 m away.

Stem:  Somewhat upright, delicate, weak, green, branching at the base, sometimes rooting at the nodes.

Form:  Delicate perennial forb.

Discussion

Oxalis is Greek for "sour", referring to the pleasantly sour taste of leaves and stem.  Stricta means "upright" referring to the upright seed pods. 

American Indians of the Great Plains tribes fed the crushed bulbs to their horses, believing that their horses would run faster.  The Kiowa chewed its leaves when they were thirsty, presumably for the effect of producing more saliva when they tasted the sour leaves and making their mouths less dry.  They called the oxalis "salt weed".  Some made yellowish-orange dye by boiling the yellow woodsorrel. 

In moderation, one can eat the leaves, flowers, or bulbs fresh in a salad or cooked.  The leaves are high in vitamin A.  However, the plant contains oxalic acid and could make someone sick if they eat too much. 

Yellow woodsorrel helps prevent erosion in waste places.

Distinguishing Characteristics

Yellow woodsorrel is recognized by its delicate form, heart-shaped leaves, and yellow flowers.  Both the leaves and the flowers fold up at night.

Distribution

This plant is found throughout eastern North America, growing on hill sides, roadsides, and other disturbed areas, as well as in gardens, flowerbeds, lawns, pastures, and woodlands.

Images

Click each small picture to see a larger image. 

October, 2003 CC	October, 2003 CC	October, 2003 CC
October, 2003 CW	October, 2003 CW

Location

N 39.26929°    W -89.89108°          
17 paces from the beginning of west end of the fitness trail, Loveless Park, South Locust Street, Carlinville, Macoupin County, IL. 

Copyright

Photos © 2003 Collin Campbell and Chris Wetherington, Carlinville High School, linke@carlinvilleschools.net       


References

Stubbendieck, James, Geir Y. Friisoe, and Margaret R. Bolick.  1994.  Weeds of Nebraska and the Great Plains.  Nebraska Dept. of Agriculture, Bureau of Plant Industry, Lincoln.  589 pp.  

Mike Haddock, Kansas State University
http://www.lib.ksu.edu/wildflower/yellowsorrel.htm

Virginia Tech Weed Identification Guide, Virginia Tech
http://www.ppws.vt.edu/scott/weed_id/oxast.htm

 Click here to return to the plant list for Carlinville High School's South-Central Illinois flora studies.