134 



KEY TO THE FAMILIES AND GENERA 



5. Canary-Grass Tribe, or Phalarideee. 



A. Glumes strongly compressed; sterile lemmas 



rudimentary 21. Phalaris. 



AA. Glumes not strongly compressed; sterile 



lemmas not rudimentary. 

 B. Sterile lemmas awned; glumes very unequal.22. Anthox- 



[anthum. 

 BB. Sterile lemmas awnless; glumes nearly equal. 23. Hierochloe. 



6. Red-Top Tribe, or Agrostideas. 



A. Lemma indurated, or at least firmer than the 



glumes. 



B. Panicle spike-like; spikeleta flattened, awn- 

 less 24. Ammopkila. 



BB. Panicle not spike-like; spikelets not Bat- 

 tened, awned. 



c. Floret oblong and with a sharp callus at 

 base; awn stout, geniculate, twisted, 



persistent 25. Stipa. 



cc. Floret ovate, the callus blunt; awn slen- 

 der, more or less deciduous 26. Oryzopsis. 



AA. Lemma of about the same texture as the 



glumes or more delicate. 



B. Spikelets crowded in dense spike-like pani- 

 cles or heads. 



c. Heads oval, very woolly 27. Lagurus. 



cc. Heads cylindrical, not woolly 28. Phleum. 



BB. Spikelets not crowded in dense heads or 



spikes. 



c. Lemma and palea much more delicate 

 and shorter than the glumes, the palea 

 shorter than the lemma, often wanting. .29. Ayrostis. 

 CC. Lemma and palea of about the same 

 texture as the glumes and as long or 

 longer. 



o. Rachilla not continued beyond the base 

 of the floret; lemma awned from the 

 tip or awnless. 



E. The lemma awned or sharp-pointed, 

 longer than the body of the awned 



or awnless glumes 30. Muchlen- 



EE. The lemma not awned or sharp- [bergia. 



pointed. 



F. Nerves of lemma 1 31. Sporobolus. 



FF. Nerves of lemma 3-5 32. Calamovilfa. 



DD. Rachilla prolonged beyond the floret as 

 a plumose bristle; lemmas awned on 



the back and silky hairy at base 33. Calama- 



[grostis. 



7. Oat Tribe, or Aveneae. 



A. Plants low, delicate; Spikelets minute 34. Aira. 



AA. Plants 1 ft. or more high. 



B. Articulation below the glumes, the spikelets 



falling entire from the pedicels, 

 c. Glumes much exceeding the 2 florets, the 



upper floret with a hook-like awn 35. Noiholcus. 



cc. Glumes exceeded by the upper floret, both 



florets awnless 36. Sphenoph- 



BB. Articulation above the glumes, these per- [oKa. 



sistent after the fall of the florets. 

 c. Spikelets 1 in. or more long, nodding, in 



an open panicle; florets all alike 37. Avena. 



cc. Spikelets about ^fin. long, erect in a nar- 

 row panicle; lower floret et animate 38. Arrhenath- 



\erum. 



8. Fescue Tribe, or Festuceae. 



A. Rachilla or lemma bearing long hairs as long 



as the lemma: tall reeds. 

 B. Spikelets unisexual; male and female 



spikelets on separate plants. 

 c. Lemmas much shorter than the glumes: 



sts. leafy throughout 39. Gynerium. 



cc. Lemmas with elongated delicate tips: 



Ivs. crowded at the base 40. Cartaderia. 



BB. Spikelets perfect. 



c. Lemmas hairy; rachilla naked 41. Arundo. 



cc.Lemmas naked; rachilla hairy 42. Pkragmiles. 



AA. Rachilla or lemma glabrous or hairy, but the 



hairs shorter than the lemmas. 

 B. Spikelets of 2 kinds, perfect and sterile, in 



the same panicle, 

 c. Fertile spikelets awnless, the sterile 



awned; panicle spike-like 43. Cynosurua. 



cc. Fertile spikelets awncd, the sterile awn- 

 lees ; panicle 1-sided , the fascicled 



spikelets nodding 44. Lamarckia. 



BB. Spikelets all alike in the same infi. 

 c. Lemmas 1 3-nerved. 



D. The spikelets subtcrete, loosely 2-4- 



fld 45. Molinia. 



DD. The spikelets compressed, densely, 



usually many-fld. 

 E. Florets membranaceous; spikelets in 



open panicles 46. Erayrostis. 



XE. Florets coriaceous; spikelets in rigid 



spike-like panicles 47. Desmazeria. 



OC. Lemmas 5- to many-nerved. 



D. The spikelet;* with several sterile 

 lemmas at the bane, strongly flat- 

 tened, in a large drooping panicle ..... 48. Uniola. 



DD. The spikelets without sterile lemmas 



at the base. 

 E. Florets crowded, nearly horizontal; 



spikelets broad, cordate .......... 49. Briza, 



EE. Florets not crowded; spikelets not 



broad and cordate. 

 F. Spikelets flattened, nearly sessile in 

 dense clusters at the ends of the 

 few panicle branches ........... 50. Dactylis. 



FF. Spikelets not flattened. 



G. Lemmas keeled, often bearing 

 white cobwebby hairs at 

 base ....................... 51. Poo. 



GO. Lemmas convex or keeled at the 



summit only, not hairy at base. 



ii. Nerves of lemma prominent, 



parallel; lemmas scarious at 



the summit ............... 52. Glycena. 



HH. Nerves of lemma not promi- 



nent, approaching each 



other at the apex; lemmas 



acute. 



i. The lemmas entire, often 



awn-tipped ............. 53. Festuca. 



II. The lemmas 2-toothed, usu- 

 ally awned just below the 

 apex ................... 54. Bromus. 



9. Chloris Tribe, or Chloridese. 



A. Spikes racemose along a common axis; 



spikelets falling entire .................... 55. Spartina. 



AA. Spikes digitate at the summit of the culm. 

 B. Spikeleta awnless. 



c. The spikes slender; spikelets 1-fld ......... 56. Cynodon. 



cc. The spikes stout ; spikelets several-fld ..... 57. Eleusine. 



BB. Spikelets awned. 



c. Fertile lemma 1-awned ................. 58. Chloris, 



cc. Fertile lemma 3-awned ................. 59. Trichloriy. 



10. Barley Tribe, or Hordeae. 



A. Spikelets solitary at each joint of the axis. 

 B. Glume 1, except in terminal spikelet; 



spikelets placed with 1 edge to the axis ____ 60. Lolium. 



BB. Glumes 2; spikelets placed with side to the 



axis. 

 c. Palea adherent to the grain; rachilla dis- 



articulating, the florets separating ...... 61. Agropyron, 



cc. Palea free from the grain ; rachilla not dis- 



articulating. 



D. Shape of glumes very narrow, l-nerved.62. Secale. 

 DD. Shape of glumes ovate, 3- to many- 



nerved ........................... 63. Triticum. 



AA. Spikelets in clusters of 2 or 3 at each joint of 



the axis. 



B. Lateral pair of each cluster pediceled, usu- 

 ally aborted, appearing like a cluster of 

 awns ................................. 64. Hordeum. 



BB. Lateral spikelets sessile, usually but 2 



spikelets at a joint ..................... 65. Elymus. 



11. Bamboo Tribe, or Bambuseae. 



A. Stamens 3: fr. a true caryopsis. 

 B. Spikelets 2- to many-fid. 



c. Infl. fasciculate ....................... 66. 



cc. Infl. racemose or paniculate, not leafy: 



sts. cylindrical : sheaths persistent ...... 67. 



ccc. Infl. spicate, leafy: sts. flattened on one 



side: sheaths early deciduous .......... 68. 



69. 



Oxytenan- 



\th?ra. 

 Arundi- 



[naria, 

 PkyUo~ 



[stachys. 

 Chusquea. 



BB. Spikelets 1-fld 

 A A. Stamens 6. 



B. Pericarp thin, adnate to the seed, the fr. 



a true caryopsis ....................... 70. Bambusa. 



BB. Pericarp, crustaceous, separable from the 



seed, the fr. nut-like .................... 71. Dendro- 



[caiamua. 



Other genera mentioned are: Cenchrus, Cephalostachyum.Cinna, 

 Dactyl octenium, Deschampsea, Diandrolyra, Distichlis, Imperata, 

 Leptochloa, Melica, Melinis, Paspalum, Rottboellia and Trisetum. 



210. LYCOPODIACE^E. 



One genus in cultivation , Lycopodium. 



211. SELAGINELLACE4S. 



One genus only Selaginetta. 



