356 
FLORA OF ADEN. 
LVI.-GRAMINEdEd 
Erect decumbent or creeping herbs, rarely suffruticose, or shrubs or 
trees ( Bambusea ) ; stems usually branched at the base, terete or com- 
pressed, with hollow or solid internodes. Leaves distichous, simple, 
usually long and narrow, generally parallel-nerved, with a sheathing 
base (sheath) distinct from the blade and rarely an interposed petiole ; 
sheath split to the base, very rarely entire, with usually a transverse erect 
appendage (ligule) consisting of a membrane or a fringe of hairs at the 
union with the blade. 
Inflorescence terminal (rarely terminal and lateral), composed of 
variously arranged spikelets, paniculate, racemose, capitate, simply or 
compoundly spicate, rarely of a single spikelet. Spikelefs consisting o£ 
an axis (rhachilla) and typically of 3 or more alternate, distichous, more 
or less heteromorphous bracts (glumes), of which the two lowest (invol- 
ucral glumes) form an involucre to the spikelet and are empty, while the 
following (floral glumes) bear in their axils subsessile flowers subtended 
by a hyaline 2-keeled or 2-nerved dorsal scale (palea) ; floral glumes 
differing usually in structure and size from the involucral glumes, and 
forming with the palea and the flower proper false flowers (florets), which 
arc alike or different in structure and sex. Flowers hermaphrodite or 1- 
sexual (often with the rudiments of the other sex), consisting of 2, 
rarely 3, minute hyaline fleshy scales (lodicules) which represent a peri- 
anth (sometimes absent), and of stamens or a pistil or both. Stamens 
usually 3, rarely 6, 4, 2, or 1, very rarely more, hypogynous ; filaments 
slender, usuilly free; anthers versatile, fugacious, with 2 parallel cells, 
usually dehiscing by a longitudinal slit. Ovary entire, 1-celled ; ovule 
erect, anatropous ; styles 2 (rarely 3 or 1,) free or connate at the base, 
usually elongate and exserted from the apex or sides of the spikelet, 
clothed with simple or branched stigmatic hairs. 
Fruit a seed-like grain, free within the flowering glume and palea 
or adnate to either or both ; pericarp very thin, rarely thick and separ- 
able from the seed. Seed erect, albumen copious, floury ; embryo 
minute, at the base of and outside the albumen ; cotyledon shield-shaped 
with an erect conical plumule and a descending conical radicle. 
Genera about 325 ; species between 3,000 and 3,500. 
Distribution : — All over the world. 
Series I . 1 2 Mature spikelets falling entire from their pedicels or 
with them, all alike or differing in sex and structure; perfect spikelets 
1 We follow in the main O. Stapf’s publications on this order. 
2 In arranging this key we followed in the main lines Dr. Stapf in the Flora capensis ” 
( 189 §). 
