Bunched Cory Cactus

Coryphantha ramillosa

Description

Bunched cory cactus, Coryphantha ramillosa, grows as a solitary, nearly spherical dark grayish-green stem about 3.5 in (9 cm) in diameter. Spine clusters (areoles) consist of from 9 to 20 gray, dark-tipped radial spines, about 1 in (2.5 cm) long, and four prominent central spines that are mottled brown and spread out in all directions. Budding occurs April to June; the showy flowers are pale pink to rose-purple, about 2 in (5 cm) wide, and appear in the spring. The oval or egg-shaped fruits are covered with tiny hairlike scales that give them a silvery appearance. This monoclinous plant reproduces sexually and is pollinated by solitary bees. The fruits are juicy and dispersal may be enhanced by vertebrates that remove it.

The species has also been known as Mammillaria ramillosa.

Habitat

Bunched cory cactus grows in loose limestone on rocky outcroppings on ledges or at the base of cliffs. It is part of the Chihuahuan Desert scrub community in the Big Bend region of Texas. The habitat elevation ranges from 2,500-3,500 ft (762-1,067 m).

Distribution

Bunched cory cactus is endemic to the Chihuahuan Desert, from Brewster and Terrill counties, Texas, southeast to the Mexican state of Coahuila.

Current populations of the bunched cory cactus are in the hills along the Maravillas and Reagan canyons of southeastern Brewster County, and in several smaller canyons farther east in Terrill County. A single, more isolated site was discovered in the Big Bend National Park. There are no current population estimates, but numbers are considered low. The status of the cactus in Mexico is unknown.

Threats

The major threat to the bunched cory cactus is livestock grazing at several of the population sites. Livestock can denude the land of its sparse vegetation, promoting severe erosion. Cattle have also been observed trampling plants, particularly seedlings. This threat is magnified by the limited numbers of the plant.

Bunched cory cactus has suffered somewhat at the hands of collectors, although the relative inaccessibility of much of its habitat offers some protection. Because populations occur mostly on private land, there are no prohibitions against collecting with the landowner's permission. The population in Big Bend National Park is threatened by the increasing popularity of the park as a recreation area, which brings more casual collectors into contact with the plant. The plant is protected by Texas state law.

Conservation and Recovery

The U. S. Fish and Wildlife Service Recovery Plan examines ways to deter illegal collection and restrict undue or unescorted recreational access to remote canyon sites where the cactus is found. An attempt will be made to locate other populations that may exist in isolated canyons. Otherwise, known population sites will be monitored, and more active measures taken to conserve the plant if numbers decline further.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
P.O. Box 1306
Albuquerque, New Mexico 87103-1306
(505) 248-6911
Fax: (505) 248-6915
http://southwest.fws.gov/

References

U. S. Fish and Wildlife Service. "Bunched Cory Cactus Recovery Plan." U. S. Fish and Wildlife Service, Albuquerque.

U. S. Fish and Wildlife Service. 1987 "Endangered and Threatened Species of Texas and Oklahoma (with 1988 Addendum)." U.S. Fish and Wildlife Service, Albuquerque.

Weniger, D. 1970. Cacti of the Southwest. University of Texas Press, Austin and London.