ENGELMANN — NOTES ON AGAVE. 295 



The point of the leaf forms a soft herbaceous bristle, or usually 

 a hard and pungent spine, of different shapes, round, or com- 

 pressed sideways, or flattened on the upper surface, or concave, 

 or channelled ; and these characters seem to be constant and of 

 specific value. 



The tissue of the leaf of most Agaves contains innumerable 

 extremely tough fibres, which, in some of the species with suf- 

 ficienly long leaves, afford, when freed from the surrounding 

 parenchyma, valuable textile material, usually called Pita, in 

 general use in their native countries, and even exported. A. 

 Americana furnishes a coarser Pita, A. rigida, and its cultivated 

 varieties are the source of the finer Sisal hemp ; other species, e.g. 

 A. heteracantka, are locally used for the same purposes. 



INFLORESCENCE. 



The flowering stem or scape shoots up from the centre of a 

 rosette of leaves, continuing the main axis ; it bears numerous 

 bractlike leaves (Hochblaetter), genera ly triangular from a 

 broad base, often attenuated into a slender tip, smaller as they 

 reach up into the inflorescence. All the vigor of the plant, all 

 the nourishment accumulated in the massive leaves and in the 

 succulent trunk, are used and exhausted in the production of the 

 inflorescence. It is well-known that A. Americana is exten- 

 sively cultivated in Mexico, principallv for the immense quantity 

 of saccharine juice prepared in its leaves for this purpose. When 

 the flowering scape shows the first signs of development, the 

 terminal bud and the innermost leaves are removed, when in 

 the basin thus formed the liquid collects and is dipped out ; on 

 an average about a gallon a day, for two or three months in suc- 

 cession, from a single plant 150 to 300 gallons in all. From this 

 juice the fermented {ftztlque) and distilled (mezcal) liquors are 

 prepared which are so generally used all over Mexico. The juice 

 which is extracted before the plant prepares to bloom is acrid and 

 not copious. 



The flowering stems are in the different species from 3 to 20, 

 and, it is said, even 30 feet high, and from a few lines to 3-5 

 inches in diameter, together with those of the allied Fourcroyas, 

 the tallest flowering stems known. 



The flowers are articulated on (usually extremely) short, per- 



