CLASSIFICATION OF ANGIOSPERMS. 235 



IV. ORDER XYRIDALES OR FARINOSE. 



The plants are mostly perennial herbs of tropical and sub- 

 tropical America. The order includes a number of families 

 among which is Bromeliace.e, to which the pineapple (Ananas 

 sativiis) belongs. Pineapple is a native of Brazil and is now cul- 

 tivated in warm countries of the eastern and western hemispheres. 

 The fruit contains a proteolytic enzyme resembling trypsin and 

 also a milk-curdling ferment. The bast fibers of the leaves are 

 used for textile purposes. Some of the Bromeliacese are epi- 

 phytic (air-plants), the best known member being probablv the 

 Florida moss (Tillandsia iisneoides) which is used in upholstery. 



The family Commelinaceie is represented in the United States 

 by Commelina or day-flower, some species of which have medic- 

 inal properties. The roots of some tropical species contain 

 saponin, as C. dcficicns, of Brazil. The rhizomes of a number 

 of species of Commelina contain notable quantities of starch and 

 are edible. The spider worts (Tradescantia) common in rich 

 soil in the United States, and the Wandering Jew {Tradescantia 

 Zehrina) commonly cultivated as an ornamental plant, also belong 

 to this family. 



V. order liliales or liliiflor^. 



The plants of this order are mostly perennial herbs with rhi- 

 zomes, tubers, bulbs, or fibrous roots. The leaves are parallel- 

 veined. 



a. LIIJACE^ OR LILY FAMILY. The plants are the 

 most typical of the Monocotyledons. They ^re scape-like herbs 

 vv^ith bulbs ; the flowers are symmetrical, and the perianth is 

 parted into six more or less distinct segments (Fig. 123) ; the 

 anthers are introse (123, A). The ovary is free, 3-locular, with 

 a single style, and the fruit is a 3-locular, loculicidal dehiscent 

 capsule. The following plants yield official drugs : 



Vcratrnui viride is a plant two to eight feet high, which is 

 characterized by the broad, clasping, strongly plicate leaves, and 

 by having the flowers in large terminal panicles (Fig. 129). The 

 plant is found in swamps and wet woods in the United States in 



