560 



thickened : culms cylindricj fistular, articulated with annular 

 tumid, seldom contracted knots : leaves solitary, sheathing 

 at each joint, the dilated petiole embracing the stem and 

 forming a sheath, the sheath very rarely narrowed at its exit 

 into a flattened or tubular petiole : the blade usually narrow, 

 seldom dilated, always undivided, nerves parallel : stipule 

 axillary at the conjunction of the sheath with the cuhn, more 

 or less short, membranaceous, ligula seldom none : flowers 

 usually green, seldom coloured, hermaphrodite, monoecious, 

 polygamous, very seldom dioecious, arranged in 1— many- 

 flowered spikelets and forming a spike, thyrse, raceme, capi- 

 tule or panicle: calyx most frequently 2-valved (glumes), 

 seldom 1-ivalyed or none : perianth (corolla) somewhat similar 

 to the glumes, 2-valved, seldom 1-valved: valvelets (palese) 

 dissimilar, outer one (inferior) usually keeled, 1 — 3-many- 

 nerved, muticous or awned, inner one (superior) usually 

 2-nerved, muticous, seldom awned, sometimes deficient : small 

 scales hypogynous, succulent, minute, irregular, 2 — 3, some- 

 times none : stamens hypogynous, three, seldom solitary or two 

 or 6, very rarely 4 or 6 or indefinite: anthers 2-celIed, 2- 

 forked," dehiscing lengthways : ovary 1-celled, 1-ovuled: styles 

 usually two, distinct or connate at the base, sometimes 1 or 3 : 

 stigmas plumose or hispidulous : fruit a caryopsis, free or 

 adnate to the valvelets : pericarp adnate to the seed, thin, 

 papery membranaceous, seldom crustaceous : albumen mealy : 

 embryo attached at the base of the outer side of the albumen : 

 cotyledon scutelliform, scooped out externally with a longitu- 

 dinal farrow : plumula naked, enclosed by its own sheath. 



Spikelets 1-flowered : glumes either none or rudimental, very 

 rarely equal in length to the valvelets, but much narrower : lower 

 valvelets 5 — 7, upper 8 — 5-nervcd. 



GENUS I. OEYZA. 

 Hexandria Dig'ynia. Sea: Syat: 

 JDeriv.' From the Arabic word, M-U&. 

 GEtr. Chae. Panicle : spikes 1-flowered : glumes two, small, 



