A genus of about 275 species (many differentiated by very minor characters), ranging from the south-western part of the United States to S. America, but with its centre in Mexico, where more than one hundred species have been described. The leaves form a rosette springing from a root-stock or short trunk, and are commonly thick and leathery; in many species they are armed with formidable teeth and terminate with a horny spine; in length they vary from a mere 6 in. to the 7 ft or more attained in species like A. atrovirens. After a period of years – never so long as the one hundred suggested by the popular name “Century Plant” – an inflorescence grows out from the heart of the rosette and, nourished by water and nutrients stored in the leaves, develops with remarkable rapidity. In the larger species it attains, in the course of a few weeks, the dimensions of a good-sized tree, heights of 30 ft being not uncommon. The rosette that bears the inflorescence invariably dies after flowering, but in many species off-sets continue the life of the plant. The inflorescence is most commonly branched, but in a minority of species it is a simple spike.
Several species, notably A. fourcrioides and A. sisalana, are grown in the warmer parts of the world for their valuable fibre. The Mexican national drink pulque is fermented from the sap of several species, A. atrovirens being the most prized. The agaves played a vital role in the pre-hispanic civilisations of Central America, providing both paper and fibre as well as pulque.
Two species are or have been grown outdoors in the British Isles and proved fairly hardy.