Texas Gardening: Texas Native Plant Pictures by color ( Yellow ), 1 by htop

htop wrote:
Berlandier's sundrops, Square-Bud primrose, Sundrops, Halfshrub Sundrops (Calylophus berlandieri - Synonyms: Calylophus berlandieri ssp. berlandieri, Calylophus drummondianus ssp. berlandieri), Onagraceae Family. native, perennial, blooms March through September

This is a bushy, usually 4 - 20 inch tall, plant (but it can grow up to 32 inches tall) that sometimes becomes woody near the base which grows in sun or part sun. Sundrops can be found in old fields and on hillsides of the Edwards Plateau and the South Texas Plains in sandy or rocky soil. There is an erect type and a more spread out groundcover form. Its leaves are narrow and spiny-toothed. The showy, crinkled, bright yellow blooms are up to 2 inches across with four, broad petals. The center of the bloom and stigma either black or yellow. The stigma is shaped like a club which is typical in Calylophus while in Oenothera the stigma is cross-shaped. The filaments of the stamens are fused to the petals and the bloom buds have prominent ribs on 4 sides giving it a square appearance. Seed is most successful if done in fall. It can also be propagated by take cuttings of new growth in early spring and sometimes even in January.

Distribution:
http://plants.usda.gov/java/county?state_name=Texas&statefip...

For more information, see its entry in the PlantFiles:
http://davesgarden.com/pf/go/128674/index.html

Note that the filaments of the stamens are fused to the petals.