322 



MONOCOTYLEDONES. 



Order 9. Dioscoreaceae. Perennial herbs with fleshy, often 

 very large tuberous rhizomes (or roots) ; twining stems ; leaves 

 stalked, often arrow- or heart-shaped, lobed, palminerved and finely 

 reticulate as in . the Dicotyledons (Fig. 313). The flower is' 

 diclinous (most frequently dioecious), regular, epigynous, small, and 



of a greenish colour, but otherwise typical (Pr3 + 3, and A3 + 3, 

 or G-3) ; in most instances 2 ovules are placed one above the 

 other in each loculus. The inflorescence is a spike or raceme, some- 

 times richly branched and paniculate. The order approaches most 

 nearly to the Amaryllidacese. 



