GRAMINEJE. (GRASS FAMILY.) 623 



ORDER 129. GBAMINEJE. (GRASS FAMILY.) 



Grasses, with usually hollow stems (culms) closed at the joints, alternate 

 ^-ranked leaves, their sheaths split or open on the side opposite the blade ; 

 the hypogynous flowers solitary in the axils of imbricated ^-ranked glumes, 

 forming a 1 - many-flowered spikelet; the lower glumes (1 or usually 2) 

 empty, the succeeding flowering glumes enclosing each a somewhat 

 smaller and usually thinner scale (called the palet) and 2 or 3 very mi- 

 nute hyaline scales (lodicules) at the base of the flower. Stamens 1-6, 

 commonly 3 ; anthers versatile, 2-celled, the cells distinct. Styles mostly 

 2 or 2-parted; stigmas hairy or feathery. Ovary 1-celled, 1-ovuled. 

 forming a seed-like grain (caryopsis) in fruit. Embryo small, on the 

 outside and at the base of the floury albumen. Roots fibrous. Sheath 

 of the leaves usually more or less extended above the base of the blade 

 into a scarious appendage (ligule). Spikelets panicled or spiked. Palet 

 usually 2-nerved or 2-keeled, enclosed or partly covered by the glume. 

 Grain sometimes free from, sometimes permanently adherent to, the 

 palet. A vast and most important family, as it furnishes the cereal 

 grains, and the principal food of cattle, etc. The terms flowering glume 

 and palet are now adopted in place of the outer and inner palets of pre- 

 vious editions, while for convenience the term flower is often retained 

 for the flower proper together with the enclosing flowering glume. (See 

 Plates 7-15.) 



SERIES A. Spikelets jointed upon the pedicel below the glumes, of one ter- 

 minal perfect flower (sometimes a lower staminate or neutral flower in 

 n. 5), or some or all of the 1-flowered spikelets unisexual in n. 10-12. 

 Glumes 4 (rarely only 2 or 3). 



Tribe I. PANICE^E. Spikelets of one perfect flower, in spikes or panicles. Flowering 



glume awnless, in fruit more rigid than the empty glumes. 



* Spikelets in 2-4 ranks on a more or less flattened rhachis. See also n. 5 ( Digitaria). 

 -t- Rhachis produced beyond the upper spikelet ; glumes 3. 



1. Spartina. Spikelets much flattened laterally in 2 close ranks. 



H- -t- Rhachis not produced above the upper spikelet (rarely in n. 8). 



2. Beckmannia. Spikelets obovate, in 2 close row&. Glumes 3 (or 4), strongly concave, 



carinate. 



3. Paspalum. Spikelets plano-convex, sessile or nearly so. Glumes 3 (rarely 2). 



4. Eriocliloa. Spikelets plano-convex, lanceolate, with a basal callus, short-pedicelled. 



* * Spikelets irregularly paniculate or spicate. 



5. Panicum. Spikelets ovate, not involucrate nor the pedicels bristly. Glumes 4, the 



lowest usually small or minute. 



6. Set aria. Spikelets in dense cylindrical spikes or panicles, the pedicels bristle-bearing. 



7. Cenchrus. Spikelets (1 - 5) enclosed in a globular spiny bur-like involucre. 



8. Amphicarpum. Spikelets of 2 kinds, one in a terminal panicle, the other subter 



ranean on radical peduncles. 



Tribe II. OKYZE^E. Spikelets unisexual or perfect, in loose panicles, with only 1 

 glumes (in our genera) and palet none. Stamens often 6. 



9. L,eersia. Flowers perfect. Spikelets much flattened. Glumes carinate. 

 10. Zizania. Spikelets unisexual. Glumes convex, narrow, 



