Tuesday, September 13, 2011

Mammillaria tetrancistra

Fishhook cactus

One of the few non-opuntia cacti found in the Mojave, Mammillaria tetrancistra is a small cactus that produces long, hooked spines, giving it its common name. These spines live up to their namesake, are quite sharp, and can inflict a painful wound on anyone foolish enough to touch them.

These cacti flower in April, and produce large, red fruits in the later part of the year.

Thursday, September 1, 2011

Anulocaulis annulatus

Wet leaf or valley ringstem

A member of the four-o-clock family, Anulocaulis annulatus is a perennial found in the Death Valley region of the Mojave desert. Growing in rocky canyons, these plants are visually distinctive because of their extreme glandularness. Large, white trichomes cover the leaves, while the stem internodes bear a thick, resinous ring at the mid point. This extreme glandularness may be a defensive mechanism against herbivory, as the resin probably gums up the mouth parts of any animal that tries to consume it.

The plant's early growth form is a basal rosete. When entering the flowering stage, they bolt, sending up long flower stalks, which can reach nearly 1.5m in height. The flowers of A. annulatus are very pretty, and form clusters at the tips of the plant's stems. After pollination, the flower develops into a ribbed nut.