Desert Night-blooming Cereus (Cereus greggii)

Main sources: Benson, Lyman, 1969, The Cacti of Arizona, Tucson: University of Arizona Press; Early, W.H., 1963, Cacti of the Southwest, Desert Botanical Garden of Arizona Science Bulletin No. 4; Phillips, Steven & Patricia Comus, eds., 2000, A Natural History of the Sonoran Desert, Tucson: Arizona-sonora Desert Museum Press; Epple, Ann, 1995, A Field Guide to the Plants of Arizona, pp. 157-8, Lew Anne Publishing Co., Mesa AZ; Pizzetti, Mariella, 1985, Simon & Schuster's Guide to Cacti and Succulents, edited by Stanley Schuler, NY: Simon & Schuster.

A relative of the much more prominent Saguaro cactus, this Cereus is typically inconspicuous, its thin, elongate stems appearing to be dead (they are lead-colored, typically 4- to 5-ribbed, and no more than 1/2" in diameter), though they may reach as high as 8 feet tall (usually however sprawling unless supported by surrounding shrubs or trees). However, after dusk in late June or early July (depending on rains), the plant erupts with bright-white, pointed-petal flowers, their fragrance "carrying as far as 100' and attracting moths and other night-feeding insects" (Epple, p. 168) These flowers fade after sunrise the following day, giving rise to reddish elliptical fruits with short spines.

This cactus is rare in our Saguaro Juniper area (sufficiently so that we have not yet managed to acquire an image). In the ground beneath each plant, a tuberous root may expand to a size approaching 50 pounds in weight, a food resource formerly exploited by Native Americans and early Hispanic settlers living here.

For images of this plant, see PCC: Desert Ecology Tucson and Desert USA image