110 TREES OF NORTH AMERICA 



becoming at its extremities not more than half as long and wide; petioles 6'-8' in length. 

 Flowers: spadix 3 long and 2| wide. Fruit ripening in May and June, '-f' in diameter 

 on a peduncle \' long; seed \' in diameter. 



Distribution. Florida, east end of Elliot's Key, and east end of Key Largo near the south- 

 ern shore, here forming a grove of 200 or 300 plants; more common on the Bahamas. 



Occasionally cultivated in the gardens of southern Florida. 



IV. LILIACEJE. 



YUCCLE. 



Leaves, alternate, linear-lanceolate. Flowers in terminal panicles; sepals and petals 

 nearly similar, subequal, withering-persistent; ovary with more or less deeply introduced 

 dorsal partitions; ovules numerous, 2-ranked in each cell; embryo subulate, obliquely placed 

 across the seed; cotyledon arched in germination. 



Yuccse as here limited consists of two American genera, Hesperaloe, with two species, 

 low plants of Texas and Mexico, and Yucca. 



i. YUCCA L. 



Trees with simple or branched stems prolonged by axillary naked buds, dark thick corky 

 bark, light fibrous wood in concentric layers, and large stout horizontal roots; or often 

 stemless. Leaves involute in the bud, at first erect, usually becoming reflexed, abruptly 

 narrowed above the broad thickened clasping base, usually widest near the middle, con- 

 cave on the upper surface, involute toward the horny usually sharp-pointed apex, convex 

 and often slightly keeled toward the base on the lower surface, the margins serrulate or 

 filamentose, light or dull green. Flowers fertilized by insects and opening for a single 

 night, on slender pedicels in 2 or 3-flowered clusters or singly at the base of the large com- 

 pound panicle furnished with conspicuous leathery white or slightly colored bracts, those at 

 the base of the pedicels thin and scarious; perianth cup-shaped, with thick ovate-lanceo- 

 late creamy white segments more or less united at base, usually furnished with small tufts 

 of white hairs at the apex, those of the outer rank narrower, shorter, and more colored than 

 the more delicate petal-like segments of the inner rank; stamens 6, in 2 series, free, shorter 

 than the ovary (as long in 1), white, with club-shaped fleshy filaments, obtuse and slightly 

 3-lobed at the apex, and cordate emarginate anthers attached on the back, the cells 

 opening longitudinally, curling backward and expelling the large globose powdery pollen- 

 grains; ovary oblong, 6-sided, sessile or stalked, with nectar-glands within the partitions, 

 dull greenish white, 3-celled, gradually narrowed into a short or elongated 3-lobed ivory- 

 white style forming a triangular stigmatic tube. Fruit oblong or oval, more or less dis- 

 tinctly 6-angled, 6-celled, usually beaked at the apex, baccate and indehiscent or capsular 

 and 3-valved, the valves finally separating at the apex; pericarp of 2 coats, the outer at 

 maturity thick, succulent and juicy, thin, dry and leathery, or thin and woody. Seeds 

 compressed, triangular, obovoid, or obliquely ovoid or orbicular, thick, with a narrow 

 2-edged rim, or thin, with a wide or narrow brittle margin; seed-coat thin, black, slightly 

 rugose or smooth; embryo in plain or rarely ruminate hard farinaceous oily albumen; coty- 

 ledon much longer than the short radicle turned toward the small oblong white hilum. 



Yucca is confined to the New World and is distributed from Bermuda and the eastern 

 Antilles, through the south Atlantic and Gulf states to Oklahoma and Arkansas, and 

 through New Mexico and northward along the eastern base of the Rocky Mountains to 

 South Dakota, westward to middle California, and southward through Arizona, Mexico, 

 and Lower California to Central America. About thirty species with many varieties 

 and probable hybrids are recognized. Of the species which inhabit the territory of the 

 United States nine assume the habit and attain the size of small trees. The root-stalks 

 of Yucca are used as a substitute for soap, and ropes, baskets, and mats are made from 

 the tough fibres of the leaves. Many of the species are cultivated, especially in countries^ 

 of scanty rainfall, for their great clusters of beautiful flowers, or in hedges to protect gar- 

 dens from cattle. 



The generic name is from the Carib name of the root of the Cassava. 





