Xerophyte

Description

Cleistocactus margaritanusSN|4742]]SN|18174]] a shrubby columnar cactus, branching basally with several stems. It has attractive yellowish bristly soft spines and orange-red S-shaped blooms, and seems related to Cleistocactus baumanniiSN|18174]]SN|4742]] subs. chacoanus. The most striking feature is the dense, golden yellow spination it possesses, which serve to protect it from the harsh sun common to its native habitat. More precisely the spines benefit the plant by reducing sun exposure and by trapping a layer of air next to the cactus body. This helps to cool the plant in the summer and keep it warm in the winter.

Flowers

Tubular, bilaterally symmetrical, curving upward, then narrowly S-haped above the pericarpels, orange-red 5-7 cm long, to 1 cm in diameter; perianth parts oblique; stamens red; stamens and style exserted. Stigma lobes green.

Spines

Several, golden yellow not differentiated as centrals and radials, straight, soft, and bristly.

Ribs

About 16.

Stem

Fairly stiff, erect or arching, to 2 m or more long, about 3,5 cm in diameter.

Fruits

Globose, red.

Areoles

Close set.