GRAMINE^. 113 



Order CXXV. GRAMINEiE. Juss. The Grass Tribe. 



Flowers in small spikelets, consisting of bracts or scales imbricated in 2 rows, 

 the exterior of which (usually 2) are called glumes, and the two that imme- 

 diately inclose the flower, paleie. Calyx and corolla none, or reduced to minute 

 scales or lodiculce, which are usually 2 in number. Stamens mostly 3 : anthers 

 versatile. Styles 2, sometimes united at the base : stigmas feathery. — Stems 

 (culms) hollow, closed at the joints. Sheaths of the leaves sjilit, or o[)en on one 

 side [yayj rarely entire), often furnished with a membranaceoiis appendage 

 (ligulc) on one side. 



CONSPECTUS OP THE TRIBES AND GENERA. 



Tribe I. ORYZEffi. Spikelets cither onc.flovvereil, with the glumes moslly abortive ; or 2 - 3-flowcrcd, one or 

 both of the lower flowers with a single palea and neuter, the terminal one feilile. Palea: somewhat 

 coriaceous. — Flowers mostly hcxandrous. 



1. Leersia. Spikelets one-flowered. Glumes none. Palea! 2, awnless. 



2. ZizANiA. Monoedous. Spikelets one-flowered. Glumes none. Palea; of the pistillate flowers awncd, membrana- 



ceous. 



Tribe 2. PH.ILARIDEjE. Spikelets perfect, polygamous or rarely monoecious : either one-flowered, without a 

 rudimentary stipe-like flower ; or 2-flowered, the flowers perfect or sterile ; or 2 - 3-flowered, tho 

 terminal flower perfect, the others incomplete. Palea; mostly indurated in fruit. 



3. Alopecorus. Spikelets onc-flowcrcd. Glumes 2, awnless, boat-shaped, united above the base. Upper palea want- 



ing : lower one awncd on the back. 



4. Phleum. Spikelets onc-flowercd. Glumes distinct, bo.it-shaped. Palesc awnless. 



5. Phaliris. Spikelets 3-floworod, awnless ; the 2 lower flowers scale-like ; upper flower perfect. Glumes 2, keeled. 



6. HoLCUs. Spikelets 2-flowercd : glumes nearly equal ; lower flower perfect, awnless ; upper one staminatc or neuter; 



the lower palea; awned on the back. 



7. HiERocHLoA. Spikelets 3-flowered ; the two lower flowers staminatc, triandrous, awned ; uppermost flower dian- 



drous, awnless. 



8. ANTHo.'iAXTHUM. Spikclcts 3-flowered ; the two lower flowers neuter, each consisting of a single awncd paica ; 



upper flower perfect, awnless, diandrous. 



Tribe 3. PANICEiE. Spikelets 2-flowered; tho lower flower incomplete, usually neuter. Glumes of thinner 

 texture than thepalcffi; the lower one often (rarely both) abortive. Pale;E more or less coriaceous, 

 commonly awnless ; the lower one concave. 



9. Paspalum. Glume single. Lower flower neuter, of a single palea, membranaceous. Perfect flower of 2 awnless 



palea;. — Flowers in spikes ; the pedicels jointed. 



10. Milium. Glume single. Lower flower neuter, of a single palea. Perfect flower awnless. — Flowers in a loose 



panicle; the pedicels not artieulatcil. 



11. Panicum. Spikelets naked : glumes 2, very unequal. Lower flower of one or two palea;. 



13. Peni^isetum. Spikelets with an involucre of several distinct bristles, 2-flovvercd : glumes two, unequal. Lower 

 flower of one or two palea;. 



13. Cenchrus. Spikelets enclosed in an indurated involucre, which is spiny or bristly externally. Glumes 2. 



Tribe 4. STIPACEjE. Spikelets one-flowered. Lower palea involute, with a simple or 3-cIeft mostly twisted 

 awn at the lip, indurated in fruit. Ovary slipitatc. 



14. Oryzopsi^. Glumes 2, memhranaecous, nearly equal, awnless. Palea; coriaceous, equal in length : awn deciduous, 



straight. Scales linear, elongated. Stipe of the ovary short. 



