(III.) GRASSES GRAMINEiE. 



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

 herbaceous plants (amonjj our species Amndinaria alone is woodyj, 

 with usually hollow, cylindrical (rarely flattened) and jointed 

 stems (culms) whose internodes for more or less of their length 

 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 spikeUis, these disposed 

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

 (the rachilUi) and two or more chaff-like, distichous bracts [glujues) 

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

 empty {nnpty glumes): in the axil of each of the succeeding bracts 

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

 are nan\ed ^oTcering g/umes.) Opposed to each flowering glume, with 

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

 two-keeled bract or prophyllum (the paUt), which frequently 

 envelopes the flower by its infolded edges. This bract is the 

 prophyllum 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 spikelet 

 may or may not be produced beyond the palet. 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 palet. Stamens, usually three (rarely two or 

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

 celled, 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 caryopsis, rich in 

 albumen. (In Sporobolus and Eleusifie 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 

 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 



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