16 THE TRUE GRASSES. 



more strongly developed than the other two, which 

 stand in front of the keels of the palese. On the 

 other hand, this very stamen may be aborted and 

 only the two posterior ones remain (Diarrhena, Ortho- 

 dada) ; where the entire whorl is rednced to a single 

 stamen (Uniola, Cinna, many species of Festuca and 

 Andropogon, etc.) this is generally the anterior one, 

 but in Elytrophorus it is posterior. We find a typical 

 two-membered whorl in Anthoxanthum, Hierochloa $ , and 

 Crypsis ; here the stamens lie in the mid-line of the 

 glumes, but in Coleanthus they alternate with the glumes. 

 Two alternating whorls occur in the majority of the 

 Bambusece and in many Oryzece.. Generally both whorls 

 have three members, but in Tetrarrhena and Microlcrta 

 they have but two. Since the following (single) carpel 

 always stands above the flowering glume no matter 

 whether the stamens are in one whorl or two, when only 

 one is present the inner must be supposed. 



The stamens always have slender, distinct, rarely 

 (St reptochceta, GigantochJoa, Oxytenanthera) monadelphous 

 filaments that are composed of thin-walled cells. In the 

 closed flower they are very short, but at the time of 

 flowering they elongate by the very rapid extension of 

 the cells. They remain straight for a time (Phleurri), or 

 suddenly become tipped over in such a way ( Triticum) 

 that the main mass of the pollen is emptied. 



The elongated, usually narrow-linear anthers have 

 a very fine connective and are versatile ; that is, the 

 filament is attached below the middle (^ or i) by a taper- 

 ing end. This circumstance assists in the scattering of 

 the pollen by the wind. Rarely the filaments are 

 attached at the base of the anthers (Coleanthus). The 

 pollen-sac usually opens by a longitudinal split which 

 proceeds from above downwards, more rarely (Andro- 

 pogonete) by a hole at the apex, which is often continued 

 into a split. The pollen is very finely granular, 

 spherical, and perfectly smooth. It is discharged in very 

 abundant masses, and scattered by the wind (except in 

 the cleistogamic species). 



The Pistil. — The pistil arises from a single carpel 



