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account deserves particularly 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, Dccaisne.) 
The hardy Chinese and Japan Tam. 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 B. transversa, E. Br. and D. 
punctata, E. Br., are both referable to D. Japonica. If 
this assumption should prove correct, then we have this Tam 
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 Tam. Continental and Insular India, also South 
Sea Islands. A high climbing prickly species, with opposite 
leaves. Eoots cylindrical as thick as an arm ; their taste 
exceedingly good. 
Dioscorea oppositifolia, L. 
India and China. Not prickly. One of the edible Tams. 
Dioscorea pentaphylla, L. 
Continental and Insular India, also South Sea Islands. Like- 
wise a good Tam. A prickly species, with alternate divided 
leaves. 
Dioscorea purpurea, Eoxb. 
India. In Bengal considered next best to D. alata. 
Dioscorea sativa, L. 
South Asia, east as far as Japan, also in the South Sea 
Islands, and North and tropical East Australia, likewise 
recorded from tropical Africa. Stem cylindrical, not prickly. 
The acrid root requires soaking before boiling. It has proved 
hardy in the Southern States of North America. 
Dioscorea spicata, Eoth. 
India. Eoot used like those of other species. 
