Two other sunflowers are widely distributed in the state. The orange sunflower (_Helianthus cucumerifolius_) grows in the sandy post oak belt, and the blue-weed (_Helianthus ciliaris_) is very abundant in West Texas. The latter is a low, branching perennial which is poisonous to sheep.
[Illustration: TEXAS COREOPSIS GOLDEN WAVE CALLIOPSIS]
Texas Coreopsis (_Coreopsis nuecensis_) was first described from plants found on the lower part of the Nueces River. It is quite widespread on the southern coastal prairie from March to May. It may be distinguished from other annual species of coreopsis by the circle of reddish-brown marks near the base of the yellow rays. The leaves are mostly basal and long-stalked.
Golden Wave. Drummond’s Coreopsis (_Coreopsis drummondii_) has showy, long-stalked heads, about 2 in. broad. They are borne on widely branched plants about a foot high. The leaves are divided into broad segments, and both leaves and stems have scattered soft hairs. It is very abundant on sandy coastal prairies in April and May and is well known in cultivation.
Calliopsis. Prairie Coreopsis (_Coreopsis cardaminefolia_) is a late-blooming annual plant, the flowers appearing in North Texas about the middle of June. It ranges from Kansas to Mexico and Louisiana. This plant greatly resembles the golden coreopsis (_Coreopsis tinctoria_), which is abundant on the coastal prairies in March and April. “Coreopsis” is derived from the Greek, meaning “bug-like,” and refers to the seed. The plants are often called tickseeds.
False Coreopsis. Fine-Leaved Thelesperma (_Thelesperma trifidum_) is sometimes erroneously called black-eyed Susan. It closely resembles the coreopsis when the flowers are in the bud stage. The flowers may readily be distinguished from those of the coreopsis because the ray flowers are not marked with a brown spot at the base and are divided into three equal lobes at the tip. The ray flowers of the coreopsis are commonly divided into four lobes, the two lateral being shorter than the two middle lobes. The leaves are finely divided into long, narrow segments.
This is one of the most widely distributed plants on the prairies from Mexico to Colorado, South Dakota, and Missouri. The yellow of Central Texas landscapes in late April and May is due to thelesperma. Scattered plants continue to bloom through the summer and fall. The plants grow 1-2 feet high and become widely branched. The disk flowers are a reddish-brown.