365 



; 



on the Dark Continent. As Uline (Engl. Nat. Ppmzenfam. 

 Nachtr. II.-IV. p. 85) uses tlie name 7). spinosa, Roxb., for the 



Ceylon plant, referred to by Commelin, which Sloane supposed 

 to be the Negro Yam, his judgment regarding the Old World 

 origin of I), cayenensis should rest on some basis other than that 

 which influenced Sloane and misled Linnaeus. 



When we come to the Malabar plant figured by llheede as 

 Mu-kelengu we have to deal with another complication. The 

 authors who have cited Rheede's figure under D. sativa. Linn, 

 include some, like Burmann in 1768, Willdenow in 1806 and 

 Presl in 1827, who have treated the plant it represents as merely 

 one form of a more or less variable species; and others, like 

 Gaertner in 1788, Aiton in 1813, Blume in 1827 and Kunth in 

 .1850, who by their descriptions or by some other indication, have 

 shown a desire to confine the name D. sativa, Linn, to a single 

 well-characterised form. The species with which Gaertner and 

 Aiton believed Mu-kelengu to be conspecific we now know to be 

 the West Indian D. martinicensis, Spreng. ; that with which 

 Blume identified Mu-kelengu we believe to have been D. bulbi- 

 fera, Linn. [1]. In the case of Kunth the intention to restrict 

 the name D. sativa to the Mu-kelengu of llheede (Hort. Malab. 

 vol. viii. p. 97. t. 51), though not satisfactorily carried out, is 

 very manifest. At last in 1864 the limitation aimed at was 

 definitely accomplished by Thwaites (Enum. PL Zeyl. p. 326, 

 note). However, as Hooker has shown, the name D. sativa 

 cannot be used for the species represented in Rheede's figure of 

 Mu-kelengu, notwithstanding the citation of that plate by 

 Linnaeus, because the figure bv Ehret (Hort. Cliff, t. 28) cited 

 by Linnaeus in 1753 must be accepted as the basis of D. sativa, 

 Linn. (Flor. Brit. Ind. vol. vi. p. 291). 



This, however, is not the only point connected with the plant 

 now being considered in respect of which we ore indebted to 

 Hooker. To him we owe the recognition in 1892 for the first 

 time of the important fact, overlooked by Linnaeus, that the 

 Mu-kelencfu of Rheede is conspecific with the plant figured by 

 Rumph as Comhilium (Herb. Amboyn. vol. v. p. 357. t. 126). 

 As a result of this oversight Linnaeus in 1754 (Amoen. Acad. 

 vol. iv. p. 131) instead of referring the Amboyna plant to D. 

 sativa, referred it to his own D. aculeata, Linn. (Sp. PL ed. 1. 

 p. 1033).* from which it differs in having stems which twine 

 to the left instead of the right and in having simple in place of 

 paniculate male spikes. The confusion thus introduced into the 

 conception of D. aculeata. Linn., has been closely parallel with 

 that inherent in the conception of 7). sativa, Linn. In- 

 corporated by Linnaeus in D. aculeata in his later writings, we 

 find Comhilium accepted under that species by Burmann in 1768 

 (Flor. Ind. p. 214 [314]). Dealing with D. aculeata, Linn., in 



* The name D. aculeata, as used in 1753, is based primarily on the citation 

 THoscorea foliis cordatis cattle aculeaio bulbifero [Hort. Cliff, p. 459), and as in 

 1 7:37 tbis phrase was applied only to the Kattii-Kelengu of Rheede (Hort. 

 Malab. vol. vii. p. 71, t. *tf) the incidence of the name D. aculeata is, as 

 Hooker has shown (Flor. Brii. Ind. vol. vi. p. 29t>), definitely limited to the 

 species figured under that name. Unfortunately the identity of the Kattu- 

 Kelengu was still doubtful to Hooker in 1892. 



