An agave can be many things, its tough gray-green spikes frozen in their waving like the stilled arms of an anemone in the desert’s long-parched sea. The bison of the Aztecs, it proffers its lathering innards as soap, its vicious brown-pointed tips to men as arrowheads or to women as threaded needles ready-made (with a strand of fibers left attached), its deep rubbery layers as condoms, its thinner dry sheets near the surface as paper, and its fibers as the thread for weaving, tough but softening with washing and time.