363 



place of I), martinicensis is taken by a Dioseorea, known there 

 as the ' Yam Poule/ with leaves that in shape and size resemble 

 those of the Martinique and Jamaica plant, but differ in 

 being widely reticulated and in subtending simple spikes. This 

 plant is included by Grisebach in I), -multi flora, Presl, which 

 D. martin icensis, Spreng. By others it is included in D. pohj- 

 gonoides, Humb. and Bonpl.,a South American species, and it may 

 ? perhaps be identical with the unnamed plant that has been 



attached in the Linnean herbarium to the one there written up 

 D. saliva. But it is certainly not the species accepted by 

 Kunth as D. polygonoides and cannot even be regarded as a 



is 



as 



Country Yam, as opposed to the Yam or 

 Linn.); by his remark 'swine are fatte 



variety of Kunth's plant so named. "Whether the % Yam 

 Poule ' be specifically distinct from D. martinicensis or not is a 

 point that can only be settled when the two are grown experi- 

 mentally side by side. Even if it should prove to be referable to 

 SprengePs plant it must be regarded as a very marked variety. 



The history of the second West India species included by 

 Linnaeus under I), sativa has not been quite so complicated as 

 that of D. mdrtihicensis , Spreng. It was taken up by Linnaeus 



w from Sloane's accounts of 1696 (Cat. p. 46) and 1707 (Hist. Jaw. 



vol. i. p. 140). In the latter work Sloane terms this the Negra 



Yammes proper (D. a lata, 

 d with these roots in Zey- 

 lan,' Sloane shows that he took it to be a species grown in Ceylon, 

 1 ubi porci cum radicibua saginantur ' which Commelin believed 

 to be the Mu-kelengit of Pheede. Linnaeus, who had not seen 

 a specimen of the ' : Negro Yam/ appears to have regarded Sloane's 

 surmise as an ascertained fact, hence his reference to the same 

 species of two plants so dissimilar as the Mu-kelencfu of Malabar 

 and the Negro country Yam of Jamaica. P. Browne in 1756 

 also terms Sloane's plant the ' Negro Yam/ but by his citation 

 under this name of Dioscorea foliis cordatis caulc tereti aculeato 



? hvlhifero shows that he did not agree with Linnaeus and that he 



considered it to be more naturallv placed in D. aculeata, Linn, 

 than in I). sativa, Linn. Since the stems of the Negro Yam are 

 very often armed low down, this judgment was a natural one 

 on the part of an author thoroughly familiar with the plant as it 

 grows, who had no apparent anxiety to establish a new species. 

 After Browne, however, little attention seems to have been paid 

 to this plant. Lamarck, and other subsequent writers, expressly 

 or implicitly excluded Sloane's plant from T). sativa, but no one 

 after Browne attempted to identify the plant of Sloane until 

 Grisebach in 1864 hazarded the suggestion that it is D. altissnna, 

 Lamk. An examination of Sloane's original specimen shows that 

 it represents the species which is still known in Jamaica as the 

 ' Negro Yam/ This species was described for the first time in 

 1789 by Lamarck as Z>. cayenensis* (Encyc. Meth. vol. iii. 



The name cayenensis was inadvertently printed cajenn* sis by Willdenow 

 m 1806 (8p. PI ed. Willd. vol. iv. p. 791). This was changed to cavennensis 

 by Sprengel in 1825 (Syst vol. ii. p. 152), and his orthography has been 

 followed by Grisebach, Kunth and others. There is nothing to show why 

 Sprengel, when correcting one of Willdenow's typographical errors, should 

 have accepted the other. Attention was directed to the correct spelling in 

 the Index Kewensis in 1893, but with little result ; the erroneous Sprengelian 

 form was again adopted by Uline in 1896 (Engl. Boi. Jahrh. vol. xxii. p. 481). 



