DEVELOPMENT OF PLANTS 



409 



it begins and the manner of opening of the bracts and extension 

 of anther and stigma. Many open between 6 and 7 A. M. on 

 pleasant days. Owing to the swelling of the lodicules, or of 

 the base of the bracts, these latter organs are forced apart, per- 



FiG. 284. Fig. 285. 



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

 enveloping bracts opened, exposing the stamens and pistil with feathery 

 stigmas. 3B, flower with outer firm bract removed — I, 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. 7 A, 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. 



mitting the extension of the stigma and anthers. The filament 

 quickly elongates and soon curves so as to allow the anther to 

 swing back and forth in the wind. The two lobes of the anther 

 now curve apart and open at their ends by a narrow slit, forming 



27 



