86 



POACEAE 



III. CAPILLARIA. 

 Annuals. 



Spikelets 3 mm. long or less, lanceolate or elliptic. 

 Leaf-sheaths pubescent. 



Stems stout : panicle usually included at the base, its many branches 



repeatedly divided and bearing numerous spikelets. " 

 Stems slender : panicle exserted, its few branches but little divided 

 relatively and bearing comparatively few spikelets. 

 Spikelets 2 mm. long, acute. 



Spikelets lanceolate, about 0.6 mm. wide. 

 Spikelets elliptic, about 0.8 mm. wide. 

 Spikelets 3 mm. long, acuminate. 

 Leaf-sheaths glabrous. 



First scale about V as long as the spikelet. 

 First scale more than y^ as long as the spikelet. 



Spikelets ovate, the panicle branches ascending: leaf-blades 1.5 



dm. long or less. 

 Spikelets lanceolate, the panicle branches very long and wide- 

 spreading : leaf-blades 2.5-4 dm. long. 

 Spikelets 5 mm. long, ovate. 

 Perennials. 



Spikelets less than 4 mm. long. 



Pedicels usually not exceeding four times the length of the spikelets, 

 often shorter than them. 

 Stems densely tufted, stiff and wiry, slender. 

 Panicle branches appressed. 

 Panicle branches at maturity spreading. 

 Stems single or not much tufted, stout, not rigid and wiry. 



Spikelets ovate, the panicle branches ascending: leaf-blades 1.5 



dm. long or less. 

 Spikelets lanceolate, the panicle branches very long and widely 

 spreading : leaf -blades 2.5-4 dm. long. 

 Pedicels usually many times exceeding the spikelets. 

 Spikelets .5-6 mm. long, acuminate. 



IV. HALOPHILA. 

 Spikelets less than 3 mm. long, obtuse or acutish. 



Panicle dense, the spikelets crowded, the first scale of the spikelet acute, 



Panicle long and narrow, loose, the spikelets rather scattered, the 

 scale of the spikelet truncate, about 3^ as long as the spikelet. 

 Spikelets 5-6 mm. long, acuminate. 



V. VIRGATA. 

 Stems tall, simple : panicle usually ample. 



VI. MAXIMA. 

 Tall stout grasses, with large leaves and ample panicles. 



first 



15. P. cnpillare. 



16. P. Philadelphicum,^ 



17. P. Oattingeri. 



18. P. flexile. 



19. P. proUferum. 



23. P. HaUii. 



24. P.fllipes. 



20. P. miliaceum. 



21. P. stenodes. 



22. P. diffusum. 



23. P. HaUii. 



24. P. filipcs. 



25. P. cognatum. 



26. P. capiUarioides. 



27. P. halophilum. 



28. P. repens. 



29. P. amarum. 



30. P. virgatum. 



31. P. maximum. 



VII. AGROSTOIDEA. 

 Innovations intravaginal, hence stems tufted ; spikelet not oblique to the 

 pedicel, the apex straight, hence equilateral. 

 Fourth scale of the spikelet sessile. 

 Ligule membranous. 



Panicle ovate, its branches at maturity widely spreading. 

 Panicle oblong, its branches erect. 

 Ligule a ring of long hairs. 



Leaf-sheaths naked at the apex ; panicle branches rigid and spread- 

 ing at maturity. 

 Leaf-sheaths pubescent with long hairs at the apex on the outside : 

 panicle branches long and slender, erect, flexuous. 

 Fourth scale of the spikelet with a distinct slender stipe. 

 Innovations extravaginal, the long stolons stout and scaly : spikelet oblique 

 to the pedicel, the apex decidedly curved, hence inequilateral. 



32. 

 33. 



agmstoides. 

 condensum. 



34. P. Combsii. 



35. 

 36. 



pseudanceps. 

 stipitatum. 



37. P. rostratum. 



VIII. DICHOTOMA. 



Leaf-blades on the stem long and narrow, linear, narrowed at both ends, 



very different from the early basal ones. 

 a. Leaf-blades erect. 



Stems 8-14 dm. tall, stout. 



Stems less than 6 dm. tall, not stout. 



Primary leaf-blades of the stem usually less than 4 mm. wide, from 

 25-50 times as long as broad. 

 Stems simple, finally with very short spikelet-bearing basal stems 

 concealed in the leaves : spikelets 2 mm. long or more. 

 Spikelets obtuse, the outer scales as long as or but little shorter 

 than the fourth scale. 

 Spikelets 2-2.5 mm. long, pubescent. 



Spikelets 3 mm. long, with a few scattered hairs near the 

 base. 

 Spikelets acute, glabrous, the outer scales manifestly exceeding 

 the fourth scale. 

 Stems finally branching at the nodes, no short basal stems : spike- 

 lets 1.5'mm. long or less. 

 Primary leaf-blades of the stem exceeding 4 mm. wide, often more 

 than 1 cm. in width. 20 times as long as broad or less. 



105. P. scahriuscvlum. 



38. P. linearifolium. 



39. P. peiiongum. 



40. P. depauperatum.. 



41. P. glabrifoUum. 



