The western wall-flower (_Erysimum asperum_), which grows in sandy areas in West Texas, is one of the showiest yellow mustards in the state. Several large-flowered purple mustards are common, including _Streptanthus bracteatus_.
Greggia (_Greggia camporum_) is a white-flowered mustard which looks like the yellow western wall-flower. The flowers are about half an inch broad and sometimes tinged with purple. The stems are about a foot high and almost concealed by the broad gray-green leaves. The woolly pods are narrow, flattened, and about half an inch long. It is one of the commonest flowers in Southwestern Texas, blooming in April, May, and June.
Spectacle-Pod (_Dithyraea wislizeni_) is a common plant on sandhills and gravelly mesas in Western Texas and ranges to Utah and Mexico. Any one seeing the seed pods will think that the common name is most appropriate. The plants grow 1-2 ft. high and are topped by the showy clusters of white flowers. The leaves and flowers are very much like those of greggia, but the fruits easily distinguish them. It was first collected by Wislizenus in New Mexico in 1846.
Herbs with tubular leaves; flowers nodding; sepals 4-5; petals 5, or absent; stamens numerous; style often umbrella-like; ovary 3-5-celled.
Yellow Pitcher-Plant. Trumpet-Leaf (_Sarracenia sledgei_) is also called trumpets, water-cup, watches, and biscuits. The last two names are suggestive of the broad, umbrella-shaped structure bearing the stigmas and occupying the center of the flower. The other names refer to the tubular, ribbed, trumpet-shaped leaves. The flowers are drooping at maturity, with 5 fiddle-shaped yellow petals and 5 shorter yellow sepals tinged with brown or red. It grows in swamps from East Texas to Alabama and is quite similar to the eastern _Sarracenia flava_. April-May.
The pitcher-plant is a most efficient collector of insects. The upper part of the leaf bends over, forming a lid whose inner surface is covered with minute honey-glands attractive to insects. The upper part of the tube is smooth, affording little foothold and causing the insect to fall into and drown in the sticky fluid given off in the lower part of the tube. Downwardly directed hairs prevent his escape. After a time his body is dissolved and absorbed by the plant. An overdose of animal food causes the browning and decay of the leaves.