About Thelocactus rinconensis (Poselg.) Britton & Rose
Thelocactus rinconensis is a small, perennial gray-green cactus. It grows 6 to 8 centimeters high, and has a diameter between 12 and 20 centimeters. It has 20 to 25 ribs marked with angular tubercles. The areoles are 2 to 2.5 centimeters apart, shaped circular or elliptical, and covered with white woolly hairs. Each areole has 3 to 4 central spines that are 6 to 8 centimeters long. This species also has up to six dark brown to black main spines, and thin radial spines that measure 1.3 to 1.5 centimeters long. Its flowers are around 4 centimeters long and 2.5 to 7.5 centimeters wide, funnel-shaped, and yellow or whitish. Flowers grow from new growth at the top of the plant. Its fruits are spherical to oblong, covered in scales, 7 to 9 millimeters in diameter, and greenish or yellowish. Its seeds are 1.7 to 2 millimeters long. This plant is found in the Chihuahuan Desert of Coahuila and Nuevo Leon, Mexico. It grows at elevations of 1200 to 1900 meters, in xerophytic shrubland on calcareous soils.
