THE DICOTYLEDONES 1679 



(a) Nectar present. E.g., Medicago. 



(b) Nectar absent. 



(i) Ventral surface of the bee comes into contact with the 

 pollen and the stigma. E.g., Genista, Ulex. 



(ii) The bee is struck on the back by the pollen and by the 

 stigma. E.g., Sarothammis. 



3. Pump arrangement. The thickened ends of the filament press out 

 the pollen in successive portions from the tip of the keel. Several insect 

 visits are necessary for pollination. 



{a) Nectar present. E.g., Lotus, AnthyUis, Hippocrepis. 

 (b) Nectar absent. E.g., Ononis, Lupinus, Coronilla. 



4. Brush arrangement. A brush of hairs on the style sweeps the pollen 

 out of the tip of the keel. Repeated insect visits are usually necessary for 

 pollination. 



(a) The tip of the style is straight. E.g., Lathyrus (Fig. 1536), Pisum, 



Vicia, Lens, Robinia. 



(b) The tip of the style is coiled. E.g., Phaseohis. 



Fig. 1536. — Lalhynis ndoratiis. Flower in 

 longitudinal section. 



SAXIFRAGALES 



It has already been explained why it is considered desirable to separate 

 the Saxifragales from the Resales. Under the present treatment the 

 Saxifragales are regarded as including only the four families: Crassulaceae, 

 Cephalotaceae, Saxifragaceae and Podostemaceae. The Saxifragales may 

 be defined as Archichlamydeae in which the plants are typically herbaceous, 

 with flowers which are actinomorphic and more or less perigynous, though 

 a few are epigynous. A corolla is present and the stamens are definite in 



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