hillside slope with calcareous gravels on over white blocky limestone outcrops. An exceptionally rich and diverse flora site less than 100 yards east of Coahuila state line.
grassy slope of volcanic rhyolite tuff rubble just below cliffs at upper canyon rim. This old switchback road has now been replaced with a new paved highway to Batopilas that greatly limits access to many former rich roadside collecting sites in the canyon.
Found this clump during a survey 3 Feb 09 and submitted the obs. to the California Natural Diversity Database along with photos of non-flowering vegetative plant. Returned to site on 10 April and found flowering plants.