Ill] 



LEGUMINOS^E 



33 



But the next departure opens up another series of 

 forms. In very many Leguminosae the "legume" only 



Fig. 31. Pterocarpus erinacens, Poir., 

 samara (E and P). 



Fig. 30. Entada polystachya, 

 lomentum (Bai). 



contains one seed, and hardly opens, in some species of 

 Trifolium, by one suture in T. pratense by a cap while 

 in many others it is totally iridehiscent, the fruit thus 

 becoming indistinguishable from an Achene. Similar 

 achenes occur in Dalbergia and allies, while others have 

 the margins prolonged into thin membranous wing-like 

 outgrowths either on one side, or end, or all round, and so 

 convert the fruit into a Samara (Fig. 31). Still more 

 remarkable is the conversion of the mesocarp into a more 

 or less fleshy mass covering a bony endocarp, and thus the 

 fruit into a Drupe, in Detariwn, Geoffroya and Andira. 

 w. iv. 3 



