There are a handful of cactus plants found in the area and they can be divided into the prickly pears with their dish-shaped pads and the cylindrical-stemmed chollas. Both types contain special structures in the leaf axils called areoles which are where spines, flowers and branches form from. The branching and fleshy stem segments have two kinds of spines, the more obvious of which are not barbed but there is a secondary much smaller set of spines called glochids which are barbed.

Coast Cholla normally blooms from April through June, with rounded rose to magenta blossoms about an inch in diameter. There are small leaves which appear on new growth but last only a few months. The end joints on the plant's stems dislodge easily and their spines attach to clothing or fur on passersby; a nuisance to us but the primary means of reproduction for the plant. This plant is abundant in the exo-Santa Monica Mountains Thousand Oaks area in and around Wildwood Park while not very common within the Santa Monica Mountains proper.

This plant was formerly classified in the genus Opuntia. The genus name Cylindropuntia means cylindrical. The species name prolifera refers to the plant's proliferation by means of off-shoots. The Valley Cholla, Cylindropuntia californica or Opuntia parryi, is a related cylindrical-stemmed cactus.

Contributed by Liz Baumann