474 



DIOSCOREACE^E. (YAM FAMILY.) 



I. S. Bermudiana, L. Leaves linear, crcet ; stem simple or sparingly 

 branched, naked or 1 -2-leaved, more or less broadly 2-winged; leaves of tho 

 spathc equal and shorter than the flowers, or the lower one mneh longer than 

 the flowers ; perianth blue, yellow in the centre ; the divisions notched and 

 bristle-awned at the apex. (S. mucronatum, Michx.) — Grassy meadows, or 

 sometimes in dry soil, Florida, and northward. July and Aug. — Stem 6'- 18' 

 high. Leaves mostly shorter than the stem. Flowers 4-6 in a spathc, £' wide, 

 opening in the evening. 



3. NEMASTYLIS, Nutt. 



Perianth 6-partcd, the divisions nearly equal and spreading. Stamens 3, dis- 

 tinct, with the subulate filaments much shorter than the elongated linear anthers. 

 Style short, 3-lohed, with the lobes 2-partcd, each division produced into filiform 

 radiating stigmas. Capsule oblong, truncated. — Herbs with coated bulhous 

 roots, linear plicate leaves, and very fugacious flowers from a 2-leaved spathc. 



1. N. COelestina, Nutt. Bulb small, roundish; radical leaves few, elon- 

 gated, sheathing; those of the stem diminishing upward, the uppermost bract- 

 like ; flowers mostly solitary, terminal ; divisions of the perianth oblong-ohovate ; 

 capsule obtusely 3-angled ; seeds angular, brown. (Ixia coelestina, Bertram) — 

 Fine barrens, Florida to Soutb Carolina, and westward. May and June. — Stem 

 H° - 2° hi'di. Flowers bright blue. 



Order 148. DIOSCOREACE^L (Yam Family.) 



Twining herbs, with' tuberous roots, ribbed and reticulated leaves, and 

 small regular dioecious flowers, in axillary spikes or panicles. — Perianth 

 G-parted, the tube (in the fertile flower) adherent to the 3-celled ovary. 

 Stamens <>: anthers 2-celled, introrse. Ovules anatropous, 1-2 in each 

 cell. Styles 3, more or less united below. Fruit mostly capsular, 3-G- 

 seeded. Embryo minute, in bard albumen. 



1. DIOSCOREA, Plum. Yam. 



Tube of the perianth 3 -winged. Stamens inserted at the base of the limb. 

 Capsule 6-seeded, membranaceous, 3 winged, opening septieidally through the 

 wings. Seeds (hit, broadly winged. — Leaves petioled, mostly cordate and entire. 

 Petioles tumid at the base. 



1. D. Villosa, L. Stem smooth (10°- 15° long) ; leaves alternate, oppo- 

 site, or whorled, broadly cordate, acuminate, 7-9-nerved, smooth, or pubescent 

 beneath, mostly longer than the slender petiole ; flowers very small, whitish; the 

 sterile ones m scattered clusters on the very slender branches of the axillary 

 panicles . the fertile in a simple spike ; stigmas notched at the apex ; capsule 

 oval or ohovate, strongly 3 winged, nodding (1) quaternata, M'ult.) —Margins 

 of swamps, Florida, and northward. July. 



