GRASSES OF NORTH AMERICA. 



GRAMINE^. 



Flowers perfect or imperfect iu little green or more or less sca- 

 rious spikes, called spikelefs, consisting of a small axis, rachilla^ 

 bearing several scalelike distichous bracts called glumes, the 2^^ 

 or sometimes 1 or rarely 3 or more lower ones and sometimes 1 

 or more upper ones empty, the other one or more floral or flow- 

 ering glumes with 1 sessile flower in the axil of each. No normal 

 })erianth, but the flower usually in a 2-nerved glumelike scale 

 called a palea (prophyllum), Avithin which are often found 2 or 3 

 very thin hyaline scales called lodicules. Stamens usually 3, 

 sometimes 2 or 1, in a few genera G-40 ; filaments distinct, filiform 

 or rarely monadelphous ; anthers usually versatile, rarely attached 

 at one end, ovate, oblong or linear, with 2 parallel . cavities without 

 any prominent connective. Ovary sessile or on a short stipe, 

 erect, 1-celled. Styles 2, lateral or rarely 3 or 1, distinct or united 

 at the base into a 2- or 3-branched style, the upper stigmatic por- 

 tion, or stigmas, either feathery with simple or branched stigmatic 

 hairs, or more rarely simple and clothed with very short papillfe. 

 Ovule 1, ascending, slightly campylotropous. Fruit a cargojms or 

 grain, usually small, often enclosed in the palea and subtending 

 glume, to the former (and rarely the latter) of which it sometimes 

 adheres, the thin membranous pericarp usually closely adnate ta 

 the seed and inseparable from it, in a few genera loosely surround- 

 ing the seed and dehiscent. Seed erect with a thin adnate testa ; 

 embryo small, on one side of the base of the endosperm (albumen). 



Annual or perennial herbs usually tufted or decumbent, rarely 



