Hymenoxys texana
Hymenoxys texana is a rare species of flowering plant in the aster family known by the common names prairie dawn, Texas prairie dawn-flower, and Texas bitterweed. It is endemic to Texas, where it is known only from the general vicinity of Houston. It is threatened by the loss of its habitat. It is a federally listed endangered species of the United States. Hymenoxys texana is an annual herb with delicate reddish or purplish stems growing only 10 or 15 centimeters (4-6 inches) tall. The leaves have rubbery, glandular blades which may be simple or divided into lobes, particularly at mid-stem. The inflorescence is a solitary flower head or an open cluster of several heads. Each head is under a centimeter wide and has 6 to 8 yellow ray florets each 2 or 3 millimeters long. The ray florets are often tucked behind the phyllaries. The center of the head has 30–75 tiny disc florets. Hymenoxys texana grows only in the grasslands of the Gulf Coastal Plain in Texas. It can be found on open, barren stretches of saline sandy soil at the base of Mima mounds. The soil is often coated with a slick of algae (Nostoc sp.) during the