CXIII. GF AMINES 
571 
CXIII. GRAMINEJE 
Annual or perennial herbs, shrubs or trees in BambusecB, often 
having underground, creeping stems or rhizomes ; roots fibrous 
or occasionally tuberous ; stems erect or decumbent, often tufted, 
terete or slightly flattened, usually hollow between the joints. 
Leaves mostly crowded near the base of the stem, the upper ones 
alternate, sheathing ; sheath split longitudinally and usually 
furnished at the top with a short appendage or ligule, which is 
membranous or scarious or reduced to a ring of hairs ; blade 
narrow, usually flat and entire, parallel-veined, the margins 
often inrolled especially when dry. Flowers generally 2 -sexual, 
in spikelets arranged in terminal spikes, racemes or panicles. 
Panicle-branches often spreading only when in flower or fruit 
and sometimes so short as to form a compact or even cylindric 
panicle. The axis of the whole inflorescence is called the 
rhachis and that of a spikelet the rhachilla. Each spikelet 
consists of 3 or several or sometimes many scale-like, keeled 
bracts or glumes arranged alternately on opposite sides of the 
spikelet, their concave faces towards its axis, and the midrib 
frequently prolonged as a bristle or awn. Usually the 2 lowest 
or outermost glumes are nearly opposite and enclose the flower or 
flowers constituting the spikelet. In a few genera there are more 
than 2 empty glumes, rarely only one. Each flower usually 
consists of a flowering glume enclosing a rather smaller, flat, 
2-nerved bract or glume, called the pale, placed with its back 
to the rhachilla or axis of the spikelet. Between the flowering 
glume and the pale is the flower proper consisting usually of 2, 
rarely more, minute, hypogynous scales called lodicules repre- 
senting the perianth in other Orders, the stamens and the ovary. 
Stamens 3, rarely more or fewer; filaments long, hair-like, usually 
free ; anthers linear, versatile, cells 2, parallel or more or less 
diverging at both ends. Ovary 1-celled, 1-ovuled, crowned by 2, 
rarely 3 or 1, feathery styles. Fruit or grain seed-like, with the 
very thin pericarp inseparable from the seed, free as in Triticum 
or adhering to the pale as in Avena or to both pale and 
flowering glume as in Hordeum. At the base of the grain is a 
scar indicating the position and shape of the usually very minute 
embryo. It is often convenient to refer to the empty and flowering 
glumes collectively as glumes ; thus a spikelet containing two 
empty and three flowering glumes is described as 5-glumed. When 
a spikelet contains more than three glumes above the empty ones the 
uppermost or the lowermost may enclose a male or only a rudi- 
mentary flower. In some genera the rhachilla is prolonged above 
the terminal flower and. naked or bearing 1-3 rudimentary glumes. 
In the following keys and descriptions the spikelets are often 
described as awned or awnless, because it is easier to put it this way 
