LEGUMINOS^ 



37 



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Fig. H5. — Flower 

 of Horse Gram. 



(a) The corolla, supported by a cup-like calyx with five long 

 points, consists of five petals which are of a creamy white colour 

 and which differ from one another in shape and size. The 

 largest of them is erect and is called the standard 

 (fig. 34, 6), because it stands up above the rest 

 and shows its colours so boldly. It might also 

 be called <'sail", for it answers the purpose of 

 one. The wind blows it round, so that it always 

 turns its back to bad weather, and serves as 

 a shield to the delicate parts within. The two 

 lateral petals are called ivlngs (fig. 34, c) and 

 the two lower ones are so combined that they 

 form a boat and are called the keel. These 

 boat-like leaves enclose the stamens and the 

 pistil (fig. 36), which latter consists of a long 

 and hairy ovary and a style. In bud the petals 

 are folded in such a way that the keel is inner- 

 most, the two wings fold over the keel, and the 

 standard envelops all (imbricate aestivation). 



ip) There are ten stamens. The filaments of nine of them 

 are united to a tube which, however, is not joined at the top. 



The filament of the tenth 

 stamen lies in the slit. It 

 is only through this slit that 

 insects, attracted by the large 

 standard and also by the 

 sweet scent the flower ex- 

 hales, can get at the honey 

 which lies hidden within the 

 tube of the filaments. While 

 trying to get at the inner parts 

 of the flower they must press 

 down the keel. At once the 

 style protrudes and touches the body of the visitor, which pro- 

 bably has come from another flower where its hairy body was 

 covered with pollen, and the ovules are thus pollinated. At the 

 same time, by the sudden jerk of the style, the stamens are 



Fig. 36. — Keel of Pea flower (3 times en 

 larged). B. Bundle of the 9 combined 



stamens (only 4 of the 9 are visible). 



St. Single stamen. A. Access to honey. 



S. Style with stigma and brush. 



