Escobaria

Escobaria vivipara- complex

E. vivipara, photo by Panayoti Kelaidis

Cold hardy, moisture tolerant, low growing form, beautiful flowers, adaptable--five key phrases to look for, when choosing a cactus to fit into your rockgarden.

Escobaria vivipara is one of these cactus. It is found in seventeen U.S. states and three Canadian provinces. With such a vast territory variability is to be expected. Again E. vivipara does not let us down. The E. vivipara complex contains nine named varieties and one closely associated species.

The varieties are: arizonica, bisbeeana, deserti, kaibabensis, neomexicana, radiosa, rosa, vivipara (the most wide spread) and buoflama (the name is an acronym of Bureau of Land Management). The associated species is Escobaria alversonii at one point considered a variety.

E. missouriensis, photo by John Weiser

The highest degree of variability occurs in the southwestern states. Var. vivipara is a low clumping mat and arizonica a cylindrical upright clumper. The other varieties fall in between these two forms.

Escobaria missouriensis is one of those bone-hardy cactus from the Northern Great Plains.

E. vivipara var. deserti,
photo by Panayoti Kelaidis

The form found in that part of the country grows very low to the ground (almost flat) tucked in amongst the short bunch grasses, on the dry sloping flanks of clay buttes and gravely knolls. It is confined to the southwestern portion of the state in what, for a better term, is know as the "bad lands."

The spines are thin and wiry with few to no central spines (a user-friendly cacti). It can take considerable moisture. Fertile seed are encased in small bright red, berry-shaped fruits, that can persist attached to the plant for up to two years. There is some variation in spine coloration from white though amber. Once in a while a black-spined plant may be discovered. These northern forms bloom with the blossoms in clusters. The petals are always a pale straw color with an embossed button of yellow stamens.

E. vivipara var. neomexicana,
photo by John Weiser

Escobaria flower from the apex as do Coryphantha and nearly all Escobaria were once included in the genus Coryphantha. The difference between these two genera is inconspicuous, Coryphantha seed coats are reticulate (have crisscrossing net like pattern), whereas Escobaria seed coats are foveolate,(pitted).

Escobaria vivipara is correct in currently accepted taxonomy.