292 DIOSCOREACEiE. Sisyrinchium. 



leaflets linear-lanceolate, tapering to a mucronate point ; in var. 1, they are about three-fourths 

 of an inch Ion"-, somewhat equal, and shorter than the flower, but often longer llian the 

 pedicels, sometimes purplish ; in var. 2, the outer leaf is often 1^-2 inches long, ex- 

 ceeding the flowers, and more frequently tinged with purple or violet. Flowers 2-5 from 

 each spathe, opening in succession, fugacious. They are about half an inch in diameter, of 

 a delicate purplish-violet, with a small yellow centre, and are supported on slender pedicels. 

 Segments of the perianth emarginate, with a central cusp. Stamens shorter than the perianth ; 

 the filaments at first cohering : anthers linear ; the cells distinct at the base. Style closely 

 surrounded by the stamens : stigmas a little spreading. Capsule globose and obscurely 3-sided, 

 the size of a small pea. Seeds about 8 in each cell, in a double row, globose-angular. 



In moist meadows, among grass, and in woods. Fl. End of May - June. Fr. July. The 

 two plants which I have here described as varieties, are considered distinct species by most 

 of our botanists, but there are many intermediate forms which seem to connect them. 



Order CXV. DIOSCOREACE^. R. Brown. The Yam Tribe. 



Flowers most.ly dioecious. Perianth 6-cleft or -parted, in a double series. Stamens 

 G, or sometimes 3. Ovary adherent to the tube of the perianth, 3-celled, 

 with one or two anatropous ovules in each cell : styles 3, united below or 

 distinct. Fruit capsular, often 3-lobed or 3-winged ; two of the cells some- 

 times abortive. Seeds flat, sometimes winged. Etnbryo minute, lying in a 

 cavity of the cartilaginous albumen. — Twining herbs or undershrubs. Leaves 

 with reticulated veins, petiolate. Flowers inconspicuous. 



1. DIOSCOREA. Plu7n.; Endl. gen. 1201 ; Grisch. Smil. 4- Diosc. in Endl. cj- Mart. 



Jl. Bras. p. 21. YAM. 



[Dedicated to the ancient Greek naturalist Dioscorides.] 



Diojcious. Sterit.e fl. Stamens 6 (3 of them sometimes barren) or only 3 : filament subu- 

 late : anthers globose-didymous. Fertile fl. Styles distinct nearly to the base : stigmas 

 linear, spreading. Ovary 3-celled, witii 2 ovules in each cell. Capsule membranaceous, 

 3-celled, triangular, wiili broad somewhat winged angles. Seeds membranaceously winged. 

 — Twining herbs or undershrubs. Rhizoma tuberous, often very large. Leaves mostly 

 alternate, sometimes opposite, cordate or hastate. Flowers very small, numerous, in 

 axillary panicles or spikes. 



