N. ORD.—DIOSCOREACEZ:. 174 
GENUS.— DIOSCOREA,* PLUM. 
SEX. SYST.—DIGECIA HEXANDRIA. 
DIOSCOREA. 
WILD YAM. 
SYN.—DIOSCOREA VILLOSA, LINN.; D. QUATERNATA, WALT.; D. PANI- 
CULATA, JACQ. 
COM. NAMES.—WILD-YAM ROOT, COLIC ROOT, RHEUMATISM ROOT,+ 
DEVIL’S BONES; (FR.) IGUAME INDIGENE; (GER.) WILDE YAM. 
A TINCTURE OF THE ROOT OF DIOSCOREA VILLOSA, LINN. 
Description.—This herbaceous, never villous twiner, usually attains a growth 
of from 5 to 15 feet over fences, bushes, and undershrubs. oot horizontal ; 
stems solarly voluble, slender. eaves variously arranged, those at the base of the 
plant sometimes in fours, those of the middle section nearly opposite, while the 
upper are alternate; 4/ade ovate, 7- to 11-ribbed, more or less downy and grayish 
beneath; Jase cordate; margin entire or wavy; apex conspicuously pointed ; 
petioles nearly the length of the blade and dilated at the base. Inflorescence in 
drooping, axillary racemes and panicles; flowers very small, dicecious, pale green- 
ish-yellow. Sterile flowers in elongated panicles; perianth 6-parted ; /odes oval; 
stamens 6, situated at the base of the lobes, included; ovary abortive, minute; 
filaments terete; anthers introrse; ce//s roundish, distinct. /ertz/e flowers in simple 
racemes; ferianth tubular ; limb cut into 6 rounded segments; s/amens 6, abor- 
tive; ovary oblong, sharply triangular, 3-celled; ovsdes 1 to 2 in each cell, pen- 
dulous, anatropous; s¢y/es very short, bifid. /7vazt an oval, 3-celled, 3-winged, 
membranaceous pod; dehiscence loculicidal into 3 valves by splitting through the 
winged angles. Seeds winged, plane, semi-conoid, 2 in each cell; evéryo somewhat 
pyriform, compressed. 
Dioscoreaceee.—This small natural order is represented in North America by 
this species only, 7 genera and about 150 species being all the representatives 
known upon the globe, and those are mostly tropical. The plants in general are 
known by the following characters : Stems twining ; roots usually tuberous, large, 
or sometimes horizontal and knotted. Leaves with a few conspicuous, parallel 
ribs, otherwise closely-netted, veined; petioles always present. /uflorescence usually | 
in axillary racemes or racemose panicles. //owers regular. Male flowers: pert- 
* Dedicated to Pedacius Dioscorides, the Greek physician and naturalist. 
+ Rheumatism Root generally alludes to Feffersonia diphylia (Berberidacez). 
