ISI 2004-3. Frailea gracillima ssp. horstii F. Ritter

The affinities of the dwarf cacti in the genus Frailea have long been recognized to lie with Notocactus, from overlapping ranges in south-central S America. However, the genus is maintained in the most recent review by Andreas Hofacker, who recognizes 17 of the more than 50 species that have been described. Frailea exhibits an interesting reproductive biology: the flowers that precede the fruits are often cleistogamous, that is, they pollinate themselves without ever opening. As a result, one sees the easily crumbled, papery-skinned fruits developing without ever having witnessed an open flower. However, under the right conditions, on hot summer afternoons, one may be fortunate enough to observe broadly open flowers inviting pollinators to visit. The flowers of the form offered here are unusually pale—a delicate shade of creamy yellow. We offer plants from self-pollination of HBG 61199. The taxon is only known to occur in a limited area around Caçapava, Rio Grande do Sul, Brazil. $5.

open flowers, more white than yellow
Photo © 2004 by John N. Trager. Images may not be used elsewhere without permission.

Published in the Cactus and Succulent Journal, Vol. 76 (2), March - April, 2004