Clavellina

Description

Grusonia schottii is a plant species in the genus Grusonia fromthe cactus family (Cactaceae). The specific epithet schottii honors the German naturalist and plant collector Arthur Schott, who helped survey the United States–Mexico border. Common names are "Clavellina", "Devil Cactus", "Dog Cholla" and "Schott Club Cactus". Grusonia grahamii grows low and forms extensive mats 7.5 to 9 centimeters high. The roots are fibrous. The club-shaped, occupied with wide and up to 2 centimeters high humps drive sections are 2 to 6.5 centimeters long and have a diameter of 1.5 to 3 centimeters. The circular areoles are covered with white to yellow wool and yellowish white to yellow glochids up to 7 millimeters long. The eleven to 17 spines are white to reddish brownare mostly located on the areoles near the tips of the shoots. The spines are spread to downward curved and 3 to 7 centimeters long. Two to three of the upper spines are ascending, spreading, somewhat round to angular and flattened and reddish brown. The lower spines are splaying or downward curved, ocher to brown, and prickly and flattened to wrinkled. The bright yellow flowers reach lengths of up to 2 centimeters. The cylindrical to ellipsoidal, yellow fruits are fleshy and covered with yellow glochids. Grusonia schottii is distributed in the United States in south and central Texas and in the Mexican states of Chihuahua, Coahuila, Nuevo León, San Luis Potosí and Tamaulipas in the vegetation of the Chihuahuanian Desert at elevations of 700 to 1200 meters. The first description as Opuntia schottii was in 1856 by George Engelmann. Harold Ernest Robinson placed the species in the genus Grusonia in 1973. Other nomenclatural synonyms are Cylindropuntia schottii (Engelm.) FMKnuth (1930) and Corynopuntia schottii (Engelm.) FMKnuth (1936) In the IUCN Red List of Threatened Species, the species is listed as "Least Concern (LC)" H. listed as not endangered. The development of the populations is unknown. The plants are either short-cylindrical and form groups or shrubby or tree-like. The roots are usually turnip-like, but sometimes fibrous. The shoots are usually divided into cylindrical to spherical segments, which sometimes have bumpy ribs. Hair, spines and glochids arise from the areoles. The pink, purple, yellow or white flowers appear laterally or almost at the top of the shoot and open during the day.