Oreocarya crassipes is a rare species of flowering plant in the borage family known by the common name Terlingua Creek cat's-eye. It is endemic to Brewster County, Texas, where it is known from only ten populations totaling about 5000 plants.[1] All of the occurrences are within a ten-kilometer radius.[2] This is a federally listed endangered species.
This is a perennial herb producing several erect stems reaching a maximum height around 25 centimeters. There is a clump of basal leaves around the stem bases. The herbage is covered in silvery soft and bristly hairs. The inflorescence is a head of yellow-throated white flowers.[2] The plants are often coated in a sooty black fungus.[1]
This plant grows only on the Fizzle Flat lentil, a small geologic formation in the Terlingua Creek watershed just north of Big Bend National Park.[3] This lentil is a unique expanse of limestone rock which is rich in gypsum and bound with clay. The formation, which locals call a "moonscape", is pale yellow in color because of its mineral makeup and about 50 feet thick.[4] The chalky rock breaks into plates and contains many fossils. The area is very dry and it receives full, hot sunlight.[5] The lentil is almost totally devoid of plant life; this species and other hardy plants, such as Castilleja elongata and Lycium berberioides, occur around the edge of the lentil.
The rare plant is limited to a specific substrate. The area is affected by human activity in several ways. The land is all privately owned and unprotected. Off-road vehicles drive on the badlands, which are used both in the mining of bentonite and for access in the grazing of livestock in the area.[1] [2]