840 GBAMINE2E. (GRASS FAMILY.) 



* * * * Spihelcts arranged along the rachis of the spikes or branches of the panicle, one sessile, 



fertile, the other pedicelled, sterile. Lower pale of perfect floweret usually awned. 



14.- BETEROPOGON. 3^ Spike solitary. Lower part of spike staminate or neuter, awn- 

 less, upper fei-tile, long-awned. 



15. AlfDROPOGON, 21 Spikes solitary, twin, or digitate-clustered, or panicled. Lower 



as well as upper part of the spike awned, and containing perfect flowerets. 



16. CHRYSOPOGON. 21 Spikelets ternate, at tip of capillary branches of spreading 



panicle. 



17. SORGHUM. 21 © Spikelets in pairs along branches of open panicle. 



18. ANTISTHIEIA. If Spikelets in nearly capitate panicles, composed of clusters subtend- 



ed by a spathe, the lower 4-8 sterile spikelets forming an involucre for the upper 



three fertile ones. 

 Series B. POACK-SI, Pedicel not jointed below glumes. Eachilla often jointed 

 above persistent glumes, produced beyond fertile flowerets, stalk-like, bearing empty pales or 

 rudimentary flowerets, or sometimes a perfect, terminal floweret, which, however, is separa- 

 ble by a joint from the sterile flowerets below it. 



Tribe V. PHAIiARIDE^. Spikelets laterally compressed, with 1, perfect 

 floweret, and with or without the rudiments of two, incomplete, lower flowerets, or 3- 

 flowered, the lower two sterile. Glumes nearly equal. Lower pale often indurated in fruit. 



19. PHALARIS. 21 Glumes nearly equal, usually winged. Inflorescence an oblong 



spike or dense panicle. 



20. ANTHOXANTHUM. The lower glume half as long as the upper, not winged. 



Inflorescence a lanceolate, spiked panicle. 



21. CRYPSIS. Glumes nearly equal, not winged. Inflorescence a dense head or short ! 



spike, with an involucre of upper leaves. 



22. COENUCOPIiE. Glumes nearly equal, not winged. Inflorescence a head, with a 



toothed, cup-shaped involucre. 



23. ALOPECUEUS. 2f Glumes nearly equal, keeled. Inflorescence an ovate oy 



globular head or cylindrical spike, in all but A. involucratus without involucre. 



Tribe VI. AGROSTIDE^. Spikelets 1-flowered, the axis jointed above the 

 glumes, not produced beyond the floweret, or produced into a stalk or bristle. Styles or 

 short. Stigmas plumose, emerging from base of spikelet. 



* Spikelet loosely panicled, the axis not produced beyond the floweret. Lower pale (except in 

 Milium) awned, 



24. AEISTIDA. 2Ji Lower pale 3-awned. Floweret stipitate. 



25. STIPA. 2t Lower pale 1 awned. Floweret stipitate. 



26. AEISTELLA. If Lower pale 1-awned. Floweret sessile. Panicle contracted. 



27. PIPTATHERUM. If Lower pale 1-awned. Floweret on a short callosity. Panicle 



diffuse. 



28. I*IILIUM. Lower pale muticous. Floweret minute, sessile. Panicle difi'use. 



* * Spikelets in a cylindrical or ovate to oblong spike, the axis beyond the floweret naked, or 



produced into a short bristle. Lower pale muticous. 



29. HELEOCHLOA. Dwarf plants, with aspect of Crypsis, and 1-2, much dilated, open, 



upper sheaths subtending each spike. Glumes muticous, not recurved at tip. 



30. EHIZOCEPHALUS. Dwarf plants with tufted, ovate-oblong spikes, overtopped by 



leaves. Glumes muticous, recurved at tip. 



31. PHLEUM. Herbs, with aspect of Alopecurus, the cylindrical or ovate-oblong spikes 



long-peduncled. Glumes mucronulate to aristate. 



* * * Spikelets small, in a compact panicle or slender spike, the axis not produced beyond the 



floweret; glumes and pale not awned. 



32. PPOROBOLUS. If Plants growing in maritime sands ; leaves pungent, glaucous. 



* * * * Spikelets small, more or less densely panicled, or in ovate to oblong heads. Lower pale 



aristate or rarely muticous. 

 t Jlxis not produced beyond floweret. 



