146 



RUMPHIUS'S HERBARIUM AMBOINENSE 



DIOSCOREA BULBIFERA Linn. Sp. PL (1753) 1033. 



Ubium pomiferum Rumph. Herb. Amb. 5: 354, t. 124. 



This species is not represented in our Amboina collections. 

 The figure, however, unmistakably represents Dioscorea bulbi- 

 fera Linn. The reduction was first made by Linnaeus, in Stick- 

 man Herb. Amb. (1754) 23, Amoen. Acad. 4 (1759) 131, Syst. 

 ed. 10 (1759) 1294, which has been followed by all authors. 

 Ubium pomiferum silvestre Rumph., 1. c. 354, is probably merely a 

 form of the same species. Mr. Burkill notes that the wild form 

 mentioned by Rumphius is in all probability Dioscorea bulbifera 

 Linn. var. vera Prain and Burkill, and that the cultivated forms 

 may include var. sativa Prain and Burkill and var. suavior Prain 

 and Burkill. 



DIOSCOREA ALATA Linn. Sp. PI. (1753) 1033. 



Ubium vulgare Rumph. Herb. Amb. 5: 346, t. 120. 



Ubium digitatum Rumph. Herb. Amb. 5: 350, t. 121. 



Ubium anguinum Rumph. Herb. Amb. 5: 351, t. 122. 



Ubium ovale Rumph. Herb. Amb. 5: 356, t. 125. 



Ubium draconum Rumph. Herb. Amb. 5: 351, t. 122, f. D, E. 



Ubium anniversarium Rumph. Herb. Amb. 5: 353, t. 123. 



Inhame St. Thome Rumph. Herb. Amb. 5: 355. 



This commonly cultivated yam is not represented in our 

 Amboina collections. However, I have little doubt that the 

 six forms figured by Rumphius as Ubium vulgare, U. digitatum, 

 U. anguinum, U. ovale, TJ. draconum, and U. anniversarium are 

 all referable to Dioscorea alata Linn., including the several forms 

 described under the first, second, and fourth. The species is 

 enormously variable in the shape, color, and size of its sub- 

 terranean parts, but is apparently fairly uniform in its vege- 

 tative and floral characters. The first three were originally and 

 erroneously reduced by Linnaeus to Dioscorea oppositifolia 

 Linn., in Stickman Herb. Amb. (1754) 22, 23, Amoen. Acad. 4 

 (1759) 131, but later authors have generally cited them as 

 synonyms of Dioscorea alata Linn., where they properly belong. 

 Ubium ovale Rumph. has been cited by some authors as a 

 synonym of Dioscorea bulbifera Linn., but from the figure and 

 description it is apparently merely the bulbil-bearing form of 

 Dioscorea alata Linn. Ubium anniversarium Rumph. has been 

 quoted by Henschel, Hasskarl, Kunth, and Miquel as a possible 

 synonym of Dioscorea spiculata Blume, but Mr. I. H. Burkill has 

 called my attention to the fact that it is the same form as the 

 curious race of Dioscorea alata figured by him in Gard. Bull. 

 Straits Settl. 1 (1915) 301, figs. 2-6, (1917) 393, pi 5, 6; and 



