PHYSIOLOGY OF THE FLOWER. 



117 



female flower possesses a nectary at its base. The lime blossoms 

 in summer, is markedly proterandrous, and characterized by fra- 

 grance and abundant nectar. Bees are excessively fond of it. 



Some smaller plants than those described are wind-pollinated, 

 as docks, sorrels (not wood -sorrel), nettles, rushes, wild plantains, 

 sedges, and grasses. 



Docks have numerous small bisexual flowers, arranged in 

 terminal and axillary racemes. Each flower can easily swing 

 about on its slender pedicel. Both calyx and corolla are incon- 

 spicuous, each consisting of three members, stamens six. The 

 syncarpous pistil possesses three short styles, each terminating in 

 a fringed stigma. 



Sorrels are similar, but the flowers are unisexual. 



Rushes possess small brown bisexual flowers, arranged in 

 panicles, and often proterogynous. All the floral leaves are in 

 alternating whorls of three, viz., three free sepals, three free 

 sepaloid petals, three outer and three inner stamens, on slender 

 filaments ; three carpels, united into a superior ovary, with short 

 style, and three rough spreading stigmas. 



Nettles {of. p. 100) are remarkable for the elastic nature of 

 their filaments, which, when the flower-buds open suddenly, scatter 

 the light pollen in the air. 



Wheat may serve as an example of a grass. The inflorescence 

 is here a compound spike, the bracts and bractlets of which are 

 overlapping scales, known as glumes. Numerous 

 spikelets are situated on the main axis, in two 

 alternating rows. Each spikelet possesses a short 

 axis, bearing from three to five sessile flowers, 

 also in two alternating rows. These flowers are 

 in axils of glumes, termed lower pales (flowering 

 glumes). Each of these is produced into a short 

 spine or awn (very long in barley). The two 

 lowest flowers are rudimentary, and the large 

 lower pales belonging to them ensheathe the base 

 of the spikelet, and receive the special name of 

 outer glumes. Each flower has an upper pale on 

 its inner side, and consists (fig. 50) of a rudimen- 

 tary perianth, three stamens, and a syncarpous 

 pistil. The perianth is constituted by two small 

 scales, the lodicules, which expand when the 

 flower is mature, force the glumes apart, and allow the essential 

 organs to project externally. The stamens, when mature, elon- 

 gate very rapidly. Their delicate filaments and versatile anthers 

 are well adapted for catching the wind. Two feathery stigmas 

 grow from the top of the superior ovary. 



Fig. 50.— Mower of 

 Grass, magnified ; 

 p. lodicules ; o- 

 ovary; s, s. fea- 

 thery stigmas ; e. 

 versatile anthers. 



