Yellow Prairie Flax (_Linum sulcatum_) is a leafy, much-branched plant, 8-16 in. tall, with large yellow petals, orange-red and veined at the base. The leaves are narrow, about 1 inch long. The flaxes have 5 styles, sometimes united, as in this plant, and sometimes separate, but often remaining on the capsule until the seeds are shed.
The yellow flaxes are sometimes separated from the blue-flowered ones and called _Cathartolinum_. There are many of them in the state, most of them so closely related that only an expert can distinguish them. They bloom from March until June. In the southern part the commonest one is the dwarf flax (_Linum multicaule_), which has its stems densely covered with short leaves. _Linum rigidum_ is a large-flowered flax with stiff stems common on prairies from Texas to Southern Canada. It has been reported as poisonous to sheep in the Pecos Valley.
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 (_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.