GRASSES 



2u: 



flesh}' in the plum, but eventually becomes fibrous in the 

 coconut. The coconut of the northern markets is the 

 stone of the ovary wall, containing one large seed. This 

 stone shows its tricarpellary structure by the ridges on 

 its surface. 



539. Grasses {Graminales) . In these plants (includ- 

 ing several families) the stems and leaves have become 

 elongated and markedly fibrous and tough. The flowers 

 are of the Lily type but much reduced, and are clustered 

 uniformly on slender axes into ''spikelets.'^ In the 

 Grasses proper (Family Poaceae) each flower is in the 

 axil of an outer bract (flowering glume, flowering scale, 

 lemma). The perianth consists of a scale-like, 2-keeled 

 calyx (palet, palea) representing the two united posterior 

 sepals (the third being absent) and of two (anterior), 

 rarely three, small, flesh}^ petals (lodicules). Two whorls 

 of three stamens each are present, or more often only 

 the outer whorl. The pistil is tri- 

 carpellary with two stigmas (very 

 rarely three stigmas) and there is 

 but one ovule in the single ovary 

 cavit3\ 



540. The Bamboos are large, 

 woody, hollow-stemmed tropical 

 grasses, in which the corolla is 

 trimerous, with the petals (lodicules) 

 relatively large, the stamens are mostly six, and the 

 pistil is frequently tristigmatic. In some bamboos the 

 fruit is externally flesh}', while in others it is like that 

 in the Brome Grasses. 



541. Brome Grass (Bromus) has a hollow herbaceous 

 stem, and its large spikelets are several flowered; the 

 corolla is reduced to two small petals (lodicules) ; the 

 stamens are three, and the pistil has two feathery 



Fig. 170. — Grass flowers 

 and spikelet. 



