FOR VICTORIAN INDUSTRIAL CULTURE. 



71 



cultivated in New Zealand, and also in tlie Southern States 

 of North America. 



Dioscorea globosa, Eoxburgh. 



India. Roxburgh states this to be the most esteemed Yam 

 in Bengal. 



Dioscorea hastifolia, Nees. 



Extra-tropic Western Australia, at least as far south as 32°. 

 It is evidently one of the hardiest of the Yams, and on that 

 account deserves j^articularly to be drawn into culture. The 

 tubers are largely consumed by the aborigines for food; it is 

 the only plant on which they bestow any kind of cultivation, 

 crude as it is. 



Dioscorea Japonica, Thunberg.* (D. Batatas, Decaisne.) 

 The hardy Chinese and Japan Yam. This species, which is 

 not prickly, has been cultivated some years in our Botanic 

 Garden. The material here for comparison is not complete, 

 but seems to indicate, that D. transversa, K. Br., and D. 

 punctata, R. Br., are both referable to D. Japonica. If this 

 assumption should prove correct, then we have this Yam 

 along the coast tracts of North and East Australia as far 

 south as latitude 33°. In Australia we find the wild root of 

 good taste. 



Dioscorea nummularia, Lamarck. 



The Tivoli Yam. Continental and Insular India, also South 

 Sea Islands. A high climbing prickly species, with opposite 

 leaves. Boots cylindiical, as thick as an arm; theii- taste 

 exceedingly good. 



Dioscorea oppositifolia, Linne. 



India and China. Not prickly. One of the edible Yams. 



Dioscorea pentaphylla, Linne. 



Continental and Insular India, also South Sea Islands. Like- 

 wise a good Yam. A prickly species, with alternate divided 

 leaves. 



Dioscorea purpurea, Eoxburgh, 



India. In Bengal considered next best to D. alata. 



Dioscorea quinqueloba, Thunberg. 



Japan, and there one of several Yam-plants with edible 

 tubers. Among numerous congeners are mentioned as 

 providing likewise root-vegetables : D. piperifolia (Humboldt) 

 from Quito, D. esurientum (Fenzl) from Guatemala, D. 

 tuberosa and D. conferta (Yelloza) from South Brazil, D. 

 Cayennensis (Lamarck) from tropical South America, D, 

 triphylla (Linne) from tropical Asia, D. deltoidea (Wallich) 

 from Nepal. Of these and many other species the relative 



