ISI 2002-3. Pilosocereus aurisetus (Werd.) Buxb. ssp. aurisetus

The name P. aureisetus might not seem the most appropriate for a plant densely clothed in cottony, white hair, but if one looks more closely, the yellow bristly spines implied by the epithet can be seen emerging from the wool. But the main charm of this plant is the whimsically unkempt appearance of its matted wool when the plant is watered overhead. Zappi’s application of the name P. aurisetus (see her Pilosocereus, the Genus in Brazil, 1994) includes among its synonyms the one given by Ritter to this form, P. werdermannianus var. densilanatus, perhaps a more descriptive name for this plant. However, Zappi’s field studies reveal that “the various characters utilized to separate [the synonyms] have proved to be very variable and more or less continuous between each population… Relative hairiness of the areoles is also variable and although this feature is developed to a striking degree in the populations named as var. densilanatus, these eventually intergrade with forms found further to the south-west…” The clone offered here is further distinguished by its slow growth and dwarf stature, rarely exceeding more than a third of a meter tall; the mature height for this subspecies may be 1 to 2 meters.

Rooted cuts of HBG 23164, a single plant grown from seed received from H. Winter in May, 1968. It was said to be seed collected by F. Ritter but with a collection number that applies to another species. It can only be said with certainty that our offering is of P. aurisetus, a species native to the state of Minas Gerais, Brazil. $6.

Photo © 2002 by John N. Trager. Images may not be used elsewhere without permission.

Published in the Cactus and Succulent Journal, Vol. 74 (2), March - April, 2002