CLASSIFICATION OF THE MONOCOTYLEDONS. 161 



which are closely set, so as to nearly conceal the flowers. The 

 flowers are either hermaphrodite or unisexual. 



There are two well-marked families, the sedges (Cyperace*ce) 

 and the grasses (Graminece). The former have solid, often 

 triangular stems, and the sheath at the base of the leaves is 

 not split. The commonest genera are Carex (Fig. 87, A, G) 

 and Cyperus, of which there are many common species, differ- 

 ing very little and hard to distinguish. There are several 

 common species of Carex which blossom early in the spring, 

 the male flowers being quite conspicuous on account of the 

 large, yellow anthers. The female flowers are in similar spikes 

 lower down, where the pollen readily falls upon them, and is 

 caught by the long stigmas. In some other genera, e.g. the bul- 

 rushes (Scirpus) (Fig. 87, H), the flowers are hermaphrodite, 

 i.e. contain both stamens and pistils. The fruit (Fig. 87, F) 

 is seed-like, but really includes the wall of the ovary as well, 

 which is grown closely to the enclosed seed. The embryo is 

 small, surrounded by abundant endosperm (Fig. 87, G). Very 

 few of the sedges are of any economic importance, though one, 

 the papyrus of Egypt, was formerly much valued for its pith, 

 which was manufactured into paper. 



The second family, the grasses, on the contrary, includes 

 the most important of all food plants, all of the grains belong- 

 ing here. They differ mainly from the* sedges in having, gen- 

 erally, hollow, cylindrical stems, and the sheath of the leaves 

 split down one side ; the leaves are in two rows, while those 

 of the sedges are in three. The flowers (Fig. 87, L) are 

 usually perfect ; the stigmas, two in number and like plumes, 

 so that they readily catch the pollen which is blown upon 

 them. A few, like the Indian corn, have the flowers unisexual ; 

 the male flowers are at the top of the stem forming the 

 " tassel," and the female flowers lower down forming the ear. 

 The " silk " is composed of the enormously lengthened stigmas. 

 The fruits resemble those of the sedges, but the embryo is 

 usually larger and placed at one side of the endosperm (N, em.), 



