538 PHARMACEUTICAL BOTANY 
raceme, at times, condensed almost to a head or capitulum (Spp. 
of clover, Mimosa, etc.). Flowers pentamerous (rarely tetram- 
erous as in Krameria), regular (Mimosacee), to irregular (Ces- 
alpinacea) to very irregular with corolla butterfly-shaped 
(Papilionacee). Sepals five united, green; petals five (rarely 
four) variously related; in Papilionacee the one superior, external 
- 
SY) 
WY, 
ALD 
Kor 
Fic. 408.—Cassia Senna—Branch showing flower and fruit. (Sayre.) 
and ‘posterior is called the standard or vexillum, the two lateral 
form the wings or ale, the two inferior, internal and anterior, 
slightly adherent, form the keel. Stamens ten to four, free, or in 
Papilionacea united by filaments into a monadelphous (ten) or a 
diadelphous (nine to one) ‘tube, inserted perigynously. Pistil 
typically monocarpellary, ovary with sutural placentation, style 
simple. Fruit a legume, more rarely becoming transformed into 
loment by transverse constrictions (Entada scandens). Seeds 
exalbuminous. 
