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PASTORAL AND AGRICULTURAL BOTANY 



tions, and iiTthe sensitive plants, represented by Mimosa pudica, a stimu- 

 lation of a terminal leaflet, for example, causes the movement of all of 

 the leaflets of the compound leaf, if the stimuli are sufficiently strong. 



FIG. 73. Details of Pea (Pisum sativum). A, Flower; B, Longitudinal section of 

 flower showing ovary, diadelphous stamens, etc.; C, diadelphous stamens and style 

 witb stigma; D, pistil of pea flower; E, seed deprived of its coats;-F, floral diagram; 

 5 = sepals; p = petals; st = stamens; c = carpel. 



The movement in the sensitive plants of this family is due to the movement 

 of water from the lower to the upper side of the pulvinus, so that the whole 



FIG. 74. A, Floral diagram of red bud (Cercis canadensis) of the sub family CAESAL- 

 PINOIDE^:; B, Diagram of wattle (Acacia latifolia) of the 'subfamily MIMOSOIDE^;; 

 b = bract; b' = bractlet; s = sepals; p = petals; st = stamens; c *= carpel; a = 



leaf drops through a considerable angle. The telegraph plant (Desmo- 

 dium gyrans) shows spontaneous movements of its leaflets upwards and 

 downwards, changing their position sometimes by as much as 180. 



