GRASSES GRAMINE^. 



Characters of the Order. — Fibrous-rooted, annual or perennial, 

 herbaceous plants (arnonj^^ our species Arundinaria alone is woody), 

 with usually hollow, cylindrical (rarely flattened) and jointed 

 steins (culms) whose internodes for more or less of their lenj^^th 

 are completely enveloped by the sheath-like basal portion of the 

 two-ranked and usually linear, parallel-veined leaves. 



Flowers without any distinct perianth, hermaphrodite or rarely 

 unisexual, solitary or several together, in spikelets, these disposed 

 in panicles, racemes or spikes, and consisting of a shortened axis 

 (the rachilld) and two or more chaff-like, distichous bracts (glumes) 

 of which the first two, rarely one or none or more than two, are 

 empty (empty glumes)\ in the axil of each of the succeeding bracts 

 (excepting sometimes the uppermost) is borne a flower,(hence these 

 are named ^oicertfior glumes). Opposed to each flowering glume, with 

 its back turned towards the rachilla, is (usually) a two-nerved, 

 two-keeled bract or prophyllum (X.\\q palea), which frequently en- 

 velops the flower by its infolded edges. This bract is the pro- 

 phyllum of the extremely short axis or branch, which supports the 

 flower; its absence indicates that the flower is strictly sessile or 

 inserted directly on the rachilla; the rachilla or axis of the spike- 

 let may or may not be produced beyond the palea. At the base of 

 the flower, between it and its glume, are usually two very small 

 hyaline scales (lodicules)\ rarely there is a third lodicule between 

 the flower and the palea. Stamens, usually three (rarely two or 

 one, or more than three) with very slender filaments and two- 

 celled, usually versatile anthers. Pistil with a one-celled, one- 

 ovuled ovary, and one to three, usually two, styles with variously 

 branched, most frequently plumose, stigmas. Fruit, a true cary- 

 opsis, rich in albumen. (In Sporobolus and Eleusine the fruit is a 

 utricle, the seed being loose within the thin pericarp.) Embryo 

 small, lying at the front and base of the seed, covered only by the 

 thin pericarp. 



The organs or parts of grasses, as in other plants, are those of 

 vegetation and those of reproduction: to the first belong the root, 

 stem or culm, and leaves; to the second the stamens and pistils. 



The Root. — Grass roots are always fibrous. The more or less 

 strong underground rhizomes are often called roots; they are not 

 true roots, but are specially modified stems. 



The Stem. — Grass stems are always branched at the base, and 

 occasionally in their upper portions. If the branches are all ap- 

 parently at the root, the culms are said to be simple, the visible 

 portion above ground being unbranched. Sometimes the stems 

 or branches stand vertically upright, when they are termed erect: 

 they may spread a little at first, and then assume an erect posi- 



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