518 SMILACE^. (SMILAX FAMILY). 



Oedeh 119. DIOSCOREACEjE. (Yam Family.) 



Plants with twining stems from large tuberous roots or knotted rootstocks, 

 and ribbed and netted-veined petioled leaves, small dioecious 6-androus and 

 regular fiowers, with the S-cleJl calyx-like perianth adherent in the fertile 

 plant to the 3-celled ovary. Styles 3, distinct. — Ovules 1 or 2 in each cell, 

 anatropous. Fruit usually a membranaceous 3-angled or winged pod. 

 Seeds with a minute embryo in hard albumen. ^- Represented chiefly by 

 the genus 



1. DIOSCOEBA, Plumier. Yam. 



Flowers very small, in axillary panicles or racemes. Stamens 6, at the base 

 of the divisions of the 6-parted perianth. Pod 3-celled, 3-winged, loculicidally 

 3-valved by splitting through the winged angles. Seeds 1 or 2 in each cell, flat, 

 with a membranaceous wing. (Dedicated to the Greek naturalist, Dioscorides.) 



1. D. villdsa, L. (Wild Yam-root.) Herbaceous ; leaves mostly alter- 

 nate, sometimes nearly opposite or in fours, more or less downy underneath, 

 heart-shaped, conspicuously pointed, 9- 11-ribbed; flowers pale greenish-yellow, 

 the sterile in drooping panicles, the fertile in drooping simple racemes. — Thick- 

 ets, New England to Wisconsin, and common southward. July. — Stems 

 slender, from knotty and matted rootstocks, twining over bushes. Pods 8"- 10" 

 long. — A bad name, for the plant is never villous, and often nearly smooth. 



Order 120. SMIEACEiE. (Smilax Family.) 



Shrubby or rarely herbaceous plants, climbing or supported by a pair of 

 tendrils on the petiole of the ribbed and netted-veined simple leaves ; with 

 dioscious small flowers ; regular perianth of 6 (rarely more} similar greenish 

 deciduous sepals, free from the ovary ; as many stamens as sepals, with in- 

 irorse 1-celled anthers ; ovary with 3 (rarely 1 or 4 - 6) cells and as many 

 elongated spreading sessile stigmas. Ovules one or a pair in each cell, 

 suspended, orthotropous. Fruit a small berry. Seed-coat close, firmly 

 adherent to the hard hco"ny albumen : embryo minute. — Order, as here 

 limited, represented almost solely by the genus. 



1 . S M I Ii A X , Tourn, Grbenbriek. Catbkiek. 



Character as above. — Flowers in umbels on axillary peduncles, greenish or 

 yellowish. Sler. Fl. Stamens inserted on the very base of the sepals : filaments 

 linear : anthers linear or oblong, fixed by the base, 2-locellate. Fert. Fl. Fila- 

 ments, if present, sterile. Stigmas thick and spreading, almost sessile. (The 

 ancient Greek name, of obscure meaning.) 



§1, Stems woody, often prickly : ovules solitary. {Ours all glabrous.) 



* Leaves ovate or roundish, ^c, most of them rounded or heart-shaped at the base, 

 and 5 - 9-nerved, the three middle nerves or ribs stronger and more conspicuous. 



