TWO-LEAVED SENNA
Two-Leaved Senna (Cassia roemeriana) gets its common name from the two spreading leaflets into which the leaf is divided. They are 1-2 in. long and have a slender stalk about the same length. The stems are commonly about 8-12 in. high, growing from a woody perennial root. The sparsely-flowered clusters of yellow flowers appear from spring until fall. The seed-pods are about an inch long and half an inch wide. This senna is very abundant from Central Texas into Mexico and New Mexico. It bears the name of Roemer, a geologist sent from Germany to study the geology of the grant made to the German colonists at New Braunfels. He was in Texas from 1845 to 1847, visited and botanized with Lindheimer at New Braunfels, and carried many new Texas plants back to Germany.
The senna group is very large and mainly tropical in distribution, many species being noted for medicinal properties. The coffee senna (Cassia occidentalis) and the American senna (Cassia marilandica) are common weeds in the eastern part of the state. The velvet-leaved or Lindheimer’s senna grows in the western part of the state.
PARTRIDGE PEA
Partridge Pea. Prairie Senna (Chamaecrista fasciculata) is also called large-flowered sensitive pea, dwarf cassia, and magoty-boy-bean. It blooms in the summer months and is very abundant in sandy soil in Central and Eastern Texas, ranging to Mexico and the northern part of the United States. The oblong leaves have 8-14 pairs of linear leaflets and a conspicuous orange or brown gland near the base. The flowers have five yellow petals, somewhat unequal and irregular in shape. Several buds grow on a short stalk between the leaves, but usually only one flower on the stalk opens at a time. It is an erect annual plant growing about 2½ feet high and often widely branched above. The pods are flattened, about ¼ in. wide and 2 in. long.
Several shrubs of the senna family are popular in Texas gardens, among them the bird-of-paradise (Poinciana gilliesii). It is a South American plant with showy yellow flowers which have 10 long brilliant red stamens protruding 3-5 inches from the flower.
RETAMA. HORSE BEAN
Retama. Horse Bean (Parkinsonia aculeata) is also known as Jerusalem-thorn, shower-of-gold, and palo verde, the latter meaning “green timber” from the green trunk and branches. It forms a spiny shrub or small tree with long, graceful, somewhat drooping branches, bearing bundles of leaves and sprays of yellow flowers. The long divided leaves are somewhat unusual. The leaf-stalks are green, broad, and flattened, performing the functions of the small leaflets which often drop off quite early. The 5 yellow petals are almost equal, but one bears a honey gland at its base and soon becomes red, remaining on the stalk longer than the others. The pods are 3-5 in. long, very narrow and constricted between the seeds. It ranges from Central Texas to Mexico and tropical America, bearing a profusion of blooms through the warm months after rains.