LEGUMINOS^E. 



469 



and by the two often more or less free claws. The 10 (5 + 5) 

 stamens (monadelphous) are either all united into one bundle, or 

 into two bundles (diadelphous), the posterior one being free (Fig. 

 512 C). The ovules are curved and also the embryo (Fig. 512 0\ 

 especially the hypocotyl, so that the radicle assumes a position 

 close to the edge of the thick, fleshy cotyledons. Endosperm 

 wanting ; the cotyledons are very rich in proteid reserve material. 

 The forms of the fruit and exceptions are described under the 

 genera. 



c- 



FIG. 512. Pisum sativum : A entire flower ; B in longitudinal section ; C gynoaceum 

 and stamens ; D gynceceum ; B' corolla dissected, e standard, a, a -wings, c keel ; D seed 

 opened to show the cotyledons (c), the radicle (r), the plumule (g) ; E fruit (legume) ; F seed. 



Geocarpic fruits, i.e. those which penetrate the soil during their development 

 and ripen underground, are found in e.fj. Arachis hypogcea (see page 472), 

 Trifolium subterrancum, Vicia amphicarpcea. Germination takes place in 

 various ways. In the majority the cotyledons are raised above the ground as 

 green, leaf -like bodies ; in the Vicieas they remain thick and white, and are 

 always enclosed in the testa, and are therefore never able to take part in the work 

 of assimilation ; in species of Phaseolus, on the other hand, they are raised well 

 above the ground and become green, but remain however thick and fleshy. 



i, 2. The two groups PODALYRIE^E (the majority of the genera are 

 Australian) and SOPHORE;E (Sophora, Edivardslx, etc.), represent the oldest 



