Leaves digitately or pinnately divided; sepals 5; petals 5; stamens 10, slightly united at base; ovary 5-celled; styles 5, free; fruit a capsule.
Drummond’s Wood-Sorrel (Oxalis drummondii) is also called sour-grass, vinegar-grass, oxalis, and violet wood-sorrel. It grows in dry soil from Central Texas to New Mexico, blooming in the late summer and fall. It has flowers like the violet wood-sorrel with similar basal leaves growing from a bulb. As a rule, the plants and flowers are larger and the leaflets are crescent-shaped. Oxalis flowers usually open in bright sunlight, and the leaves close at night.
Violet Wood-Sorrel (Oxalis violaceae) is very abundant in the woods of East Texas and on into the Western United States. The plants are generally about six inches high. Children often eat the leaves, but a considerable quantity will cause violent convulsions. The poisoning is due to the presence of oxalic acid crystals, which give a sour taste to the leaves.
The bulbs of many wood-sorrels are potted in the fall to provide house flowers in February and March. Drummond’s wood-sorrel makes an excellent border plant.
YELLOW WOOD-SORREL
Yellow Wood-Sorrel (Oxalis texana) is a large flowered wood-sorrel in East Texas. The golden-yellow petals are about ¾ in. long. The flower stalk is about twice the length of the stem and leaves. It differs from the large-flowered wood-sorrel of the Southern States (Oxalis macrantha) by having smooth instead of hairy stamen filaments.
Many of the yellow wood-sorrels are common weeds throughout the state. There are many different species. The white or pink-flowered wood-sorrel (Oxalis acetosella) is considered by many people as the shamrock of Ireland; but others consider white clover (Trifolium repens) as the true shamrock.
Dichondra-Leaved Wood-Sorrel (Oxalis dichondraefolia) is a low plant of Southern Texas and Mexico which has pale yellow flowers like the yellow wood-sorrels, but the leaflets differ in being rounded and entire and resemble the leaves of the dichondras (see [page 101]).