524 



ANGIOSPERMAE—MONOCOTYLEDONES 



each forming a boat-shaped cavity, in which the pollen rests while the air is calm. 

 When the anthers are shaken by wind, this is removed little by little, until the loculi 

 are completely empty. 



Fig. 418. Arrhenantherunt clatius, Mert. et Koch (after Kerner). (i) Undehisced anther. 2) 

 Dehisced do. (3) Spikeletwith open glumes, and anthers hanging down in still air. (4) Do., when 



the air is in motion. The anthers of one flower are sheddinfj their pollen, those of another have already 

 done so (and one has dropped from its filament), those of a third have not dehisced and are pushing their 

 way out from between the glumes. 



1000, Avena L. 



3023. A. Scheuchzeri All. — Kirchner (' Beitrage,' p. 8) describes this species 

 as homogamous, but the stigmas remain receptive and hang down between the 

 glumes when the anthers have fallen. 



3024. A. pubescens L. — This species, according to Kirchner (' Flora v. Stutt- 

 gart,' p, 134), is feebly protogynous with persistent stigmas. The anthers do not 

 dehisce until a short time after the divergence of the glumes, while the stigmas are 



