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.Cryptantha crassipes. Center for Plant Conservation. All of the occurrences are within a ten-kilometer radius.Cryptantha crassipes. The Nature Conservancy. This is a federally listed endangered species.
Description 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. The plants are often coated in a sooty black fungus.
Distribution and habitat 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.Cryptantha crassipes. Texas Parks and Wildlife. 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.USGS. Geologic Unit: Fizzle Flat. National Geologic Map Database. The chalky rock breaks into plates and contains many fossils. The area is very dry and it receives full, hot sunlight.USFWS. Final rule to list the plant Cryptantha crassipes (Terlingua Creek Cat's-eye) as endangered. Federal Register September 30, 1991. 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.
References
External links USDA Plants Profile
Further reading Moon, C. G. (1953). Geology of Agua Fria Quadrangle, Brewster County, Texas. Geological Bulletin 64:2 151.