128 A TEXT-BOOK OF GRASSES 



ropogon), or the margins may be greatly enlarged (Ixo- 

 phorus). The palea is reduced to a nerveless scale or may 

 be obsolete in Agrostis and in species of Andropogon. 

 The palea usually falls from the rachilla together with 

 the lemma but may be persistent upon the axis (e. g., 

 Eragrostis, Fig. 51). 



159. The lodicules are small organs found at the base 

 of the floret, outside the stamens. They are usually 2 

 in number, standing in front of the lemma, close together. 

 A third lodicule is present in a few genera and is placed 

 in front of the palea. In the anomalous bamboo genus 

 Ochlandra there are several lodicules. The function of the 

 lodicules is to open the floret at anthesis. They become 

 turgid and thus spread the lemma and palea apart, later 

 collapsing and allowing the floret to close by its own 

 elasticity. The lodicules are interpreted by some to be 

 homologous with the divisions of a perianth of which only 

 2 divisions have usually persisted. 



160. The stamen consists of a delicate filiform fila- 

 ment and a 2-celled anther, opening by longitudinal slits. 

 The anthers are basifixed but so deeply sagittate, as to 

 appear versatile. There are usually 3 stamens, 1 standing 

 in front of the lemma and 1 opposite each edge of the palea. 

 Sometimes there is a second whorl inside of the first and 

 alternating with it, making 6 stamens (most bamboos, 

 many Oryzese). There are various departures from these 

 numbers. There may be only 2 (Diarrhena), or only 1 

 (Cinna), rarely 4 in 2 whorls, and in certain anomalous 

 genera more than 6 (Pariana, Luziola, Ochlandra). The 

 filaments are more or less connate in a few bamboos and 

 in Streptochaeta. 



From the standpoint of evolution, the species with 6 stamens 

 in 2 whorls probably represent a more primitive form as this structure 



