THE DEUG DIOSCOREA. 19 



of the stem, however, the transition from leaves to subulate bracts is 

 not gradual but sharp. 

 Specimens examined : 



Sorth Carolina. — CMiieston County (specimen in Herb. Bost. Soc. Nat. Hist.). 



Georgia. — Jefferson County, M. II. Hopkins, 91 ; Sumter County, R. M. Harper, 

 13S9. 



Florida. — Columbia County, P. H. Rolfs, 266; Escambia County, A. H. Curtiss, 

 in 1885. 



THE DRUG DIOSCOREA. 



According to Mr, C. G. Lloyd the rhizome of Dioscorea was first 

 brought to the attention of " botanic physicians " by Dr. J. L. Rid- 

 dell " in 1835, although before that time it had been used more or less 

 as a " secret remedy." ^ Riddell's account of the plant, which was 

 copied in part by most subsequent writers, was as follows : 



1501. Dioscorea villosa, Linn. Yam root. China root. May-June. Yellow- 

 wliite. Climbing vine, G to 12 f. Koot woody, tortuous, echinate. Open woods. 

 Bottom lauds. Western States. An infusion of the powdered root is to be boiled 

 in a pint of water, and half of it given at once. * * * I have been informed 

 that Doctor Miller, of Neville, Ohio, values the tincture highly as an expectorant. 

 He says it is also diaphoretic, and, in large doses, emetic." 



In 1836, a year later, William Hance'' published a much fuller 

 account of Dioscorea, which, on account of the evidence it affords 

 regarding the identity of the species used at that time, is here quoted 

 in full: 



Dioscorea villosa. Common names — Yam root, China root. — This plant is a 

 twining and climbing vine, resembling in some respects the morning glory. The 

 i-oot is of a most singular tortuous form, of a woody consistence, with numerous 

 spiny protuberances. It is perennial, and doubtless endures a greater number of 

 years than the roots of most plants of similar habits. The sprangles are usually 

 near half an inch in thickness, and the whole root in favorable situations is 

 often found to weigh half a pound. The stem is a climbing annual vine, winding 

 around small shrubs, and insinuating itself among brambles, often attaining 

 the height of 6 or 8 feet. Near the ground the leaves usually appear in ver- 

 ticillate clusters, or whorls, varying in number from two to eight or more in a 

 bunch, dependent on the luxuriance of the soil. Higher up the leaves are alter- 

 nate. They are always on pretty long footstalks and of the form of a heart, with 

 the point acute and turned to one side ; commonly roundish as well as cordate 

 and nearly 2 inches across. Almost always you may count just nine nerves 

 or portions of framework, proceeding from the base toward the apex. The 

 flowers show themselves in May and June; they are very small and white, 

 arranged on little stems which come out just above the leaves. The seeds are 

 triangular, some like buckwheat, though four times as large, with wings at the 

 angles. The yam root grows plentifully in the Western States, delighting in 

 fertile hillsides, thickets, and open woods. 



a A Synopsis of the Flora of the Western States (1835). 



^ See Transactions, N. Y. State Eclectic Medical Society, for 1870. D. E. Smith, 

 " Dioscorea." 



c Howard's Botanic Medicine, ed. 3 (1836), ii, p. 240. 

 189 



