The genera Neobuxbaumia and Pachycereus contain the tallest and most massive columnar cacti as well as the most charismatic plants. Neobuxbaumia is of a somewhat narrow distribution and inadequately studied. Some species are confined to one canyon in southern Mexico. The genus includes at least one, probably more undescribed species. Pachycereus has become a bit of a dumping ground for monotypic genera, even if they are only vaguely related to those columnar cacti whose flesh turns black when cut, as Arthur Gibson pointed out. Both genera cry out for further research, both field and laboratory.
David Yetman is a research social scientist at the University of Arizona, where he received his Ph.D. in philosophy in 1972. A former Pima County supervisor, his studies have focused on the peoples and plants of the state of Sonora, Mexico. His book The Great Ones: Biogeography and Ethnobotany of Columnar Cacti will be available in the fall, 2007 from the University of Arizona Press. Other publications include Sonora: an Intimate Geography; Guarijíos: Hidden People of Northwest Mexico; and, with Thomas Van Devender, Mayo Ethnobotany: Land, History and Traditional Knowledge in Northwest Mexico. He is editor with Paul S. Martin of Gentry's Río Mayo Plants.
Yetman is host of the nationally syndicated PBS program The Desert Speaks. He reports that he cannot get enough of the Sonoran Desert or Latin America.
Please join us for this great program by David Yetman. It will be our first presentation and the start of another great year for the Tucson cactus and Succulent Society.