steep slope of volcanic rhyolite tuff rubble just below cliffs at upper canyon rim. This site has been destroyed by a new paved highway to Batopilas that also limits easy access to many former rich roadside collecting sites in the canyon.
on limestone gravels of wide canyon bottom. NOTE: hard horny yellow margins of leaf blades and lack of marginal fibers. This is the large handsome form once known by the synonym Y. rostrata.
slender, caulescent, long leafed yucca placed under Y. valida by Wiggins (1980) and is often mistakenly so recorded in many collections. Distinctive Cape Region endemic in thorn scrub thicket on coarse granitic soil of gently sloping coastal plain.