4GS REV. a. H-ENSLOW ON GEXTSTA TINCTORTA, 



Note on tlie Structure of Genista tiyictoria^ as apparently affording 

 facilities for the intercrossing of distinct flowers. By the Eev. 



Geoboe HenI'low, M.A., F.L.S. 



[Read April 16, 1868.] 



Indigoft 



(Linn. Journ. vol. ix. p. 355), the present writer observed a re- 

 markable peculiarity in the claws of the keel petal — in that they 

 curled backwards, if the flower was touched in imitation of an 

 insect thrusting its proboscis to the base of the calyx. The ex- 

 panded part of the carina dropped down vertically, and the alae. 

 Laving lost their support, fell laterally, so that the stamens and 

 pistil became exposed. A somewhat similar peculiarity is found 

 to obtain in the genus Genista ; but in this instance the claws of 

 the alsD curl back as well as those of the keel petals. The alae, 

 moreover, are not supported by horn-like processes projecting from 



idigofera^ but cling to the latter by 

 means of small protuberances, which fit into corresponding de- 

 pressions on the keel petals. Various modifications of this latter 

 point of structure are of very general occurrence amongst papilio- 

 naceous corollas. 



On passing any pointed object, in imitation of an insect, down 

 the medial line of the vexillum, the claws of the alse and carina 

 instantly curl backwards, and throw the expanded portions of 

 those petals into a downward and vertical position, at the same 

 time apparently jerking the stamens and pistil upwards, so that, 

 when equilibrium is restored, the staminal column is almost erect 

 and remains closely adpressed against the vexillum. 

 . There is no tendency to curvature of the stamens as occurs in 

 3Iedicago (see Linn. Journ. vol. ix. p. 327), though a slight upward 



movement seems to take place as the petals fall ; their mona- 

 delphous character would probably, as there suggested, prevent 

 such curvature. 



;No opportunity occurred of observing what insects effected the 

 above process ; but cut flowers, allowed to open in water, invariably 

 withered without expanding further by the depression of the pe- 

 tals as described. 



