394 



THE GRAMINALES 



distinguished by the usually hollow aerial stems, two rows of 

 leaves with sheathing bases split and the fruit is generally a 

 grain (Fig. 284, 6). The sedges are largely paludose and of 

 little value, the stems and leaves being often silicified. They 



Fig. 284. 



Fig. 285. 



Fig. 284. Flower and fruit of grass: 2,A, a single flower with the two 

 enveloping bracts opened, exposing the stamens and pistil with feathery 

 stigmas. t,B, flower with outer firm bract removed — /, lodicules; st, stigma. 

 6, mature fruit or grain — e, region of embryo. 7, section through base of 

 grain, showing the root, stem leaves, and scutellum, sc, or absorbing organ 

 of the embryo; en, endosperm. yA, diagram of a few of the outer cells of 

 the scutellum, sc. 



Fig. 285. Inflorescence of one of the sedges, Carex: p, spike of pistillate 

 flowers, each pistil is surrounded by a papery sac, through which the style 

 and stigma protrude; s, spike bearing staminate flowers. Note the triangu- 

 lar stem, a characteristic of this large genus of over 1,000 species. 



usually have solid stems, three rows of leaves with sheathing 

 bases entire, more simple flowers and the fruit is usually an 

 akene (Fig. 285). 



