ANNALS OF NATURAL HISTORY. 



XVI. — On the Irregular Form of the Flower of the Papilio- 

 naceae. By H. Walpers*. 



The irregular form of the flower of the Papilionacece has given 

 rise to the most varied explanations, to such an extent indeed, 

 that the enumeration of all the opinions hitherto advanced re- 

 specting the origin of this form, which, according to the point 

 of view in which they have been considered, differ essentially 

 from one another, would occupy too much space to be stated 

 here. It might consequently appear almost superfluous to 

 increase the great number of theories advanced on this inter- 

 esting subject by another ; and I would on that account have 

 held back my views, w hich differ from all hitherto brought for- 

 ward, did I not find them to be confirmed by all the researches 

 which I have made relative to the subject. 



The pod so peculiar and so characteristic [legumen) be- 

 longing to the entire family of the Leguminos^e, must, from 

 its disposition, be regarded as the single carpel of a five car- 

 pellary fruit. DeCandolle has already drawn attention to 

 this, without any botanist however having hitherto made 

 use of this fact, (proved by the pentagynous genus Affonsea, 

 A. St. Hilaire,) in explanation of the irregular form of the 

 papilionaceous flower. These five pods of Affonsea are ar- 

 ranged in a circle, so that their superior seminiferous sutures 

 are situated innermost ; the individual pods have therefore to 

 be considered as eccentric from the imaginary floral axis which 

 passes through the point of union of the margins of the pods. 

 Of these five ovaries normally four become abortive, from 

 reasons it is true unknown, and a single one only remains, 

 although exceptional cases occur of two and three ovaries in 

 one flower. This sole remaining ovarium stands eccentric from 



* Translated from the Linnaea, ein Journal fiir die Botanik, Part IV. 

 Vol. xiii. 1839. 



Ami, Nat. Hist, \o\, 5, No. 30. ilf«y 1840. m 



