Selenicereus brevispinus, or Moon Cactus, is native to Cuba. The 1 inch (2.6 cm) wide stems with 8-10 low ribs scramble across the ground and climb by aerial roots. The areoles are tawny, at first, with white hairs. They have very small spines approximately 3/64 of an inch (1-2 mm) long; radial spines are curved and the central spine is thicker. They are of easy culture and are hardy in the landscape in USDA zones 9-11.
Blooming: In late spring to early summer, the nocturnal flowers open at night and close in the morning. The large, white flowers are somewhat fragrant. Individual flower will reach to 10 inches (25 cm) long and are very showy. Probably bat pollinated, this pendulous flower opens after sunset and closes by daybreak. The image you see was taken at 3 AM!
Culture: Selenicereus brevispinus need partial shade with a well drained soil mix. In the greenhouse, we grow them in hanging baskets with a soil mix that consists of 1 part peat moss to 2 parts course sand to 1 part loam. The plants are well watered and then allowed to dry before watering again. They are fertilized only once during the growing season. Too much fertilizer will cause a lot of lush growth at the expense of flowers. Older plants in the greenhouse bloom freely. During the winter months, the night time temperatures are never allowed to go below 55°F (13°C). Water is restricted only enough to keep the stems from shriveling.
Propagation: Selenicereus brevispinus is propagated by cuttings and from seed, Fresh seed germinates readily.
Selenicereus brevispinus was featured as Plant of the Week July 8-14, 2005.
Note: I have received an email from Ulf Eliassson indicating that the specimen is, in fact, Selenicereus donkelaari. We have no systematics experts to consult with on this and the images on the internet have not been definitive. As always, I am happy to hear from viewers who know more than we do about some of our plants. -SR
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.