POACEAE 



Spikelets less than 1 mm. long. 

 Spikelets 1-2 mm. long. 



Ligule 0.5 mm. long to almost wanting. 



Blades of the primary stem-leaves, the larger 



ones, 8-15 mm. wide. 



Spikelets 1.3 mm. long : basal leaf-blades 

 equalling or larger than those on the 

 stem which are usually 5-7 in number. 

 Spikelets 1.5mm. long or more : basal leaf- 

 blades smaller than those on the stem 

 which usually number 4 or less. 

 Upper surface of the blades very rough. 

 Upper surface of the blades smooth : 

 stems much-branched : sheaths in- 

 flated. 

 Blades of the primary stem-leaves, the larger 



9nes, rarely exceeding 6 mm. wide : 

 With a broad cartilaginous white much- 

 thickened margin. 

 Upper portion of the stem naked, the 2 



leaves below the middle. 

 Stems leafy almost to the panicle: 



leaves usually 3. 



With no conspicuous white margin. 

 Leaf-blades glabrous on both surfaces. 

 Spikelets barely exceeding 1 mm. 

 long, obovoid : primary leaf- 

 blades 5-7 cm. long. 

 Spikelets 1.5 mm. long, elliptic : pri- 

 mary leaf-blades usually less 

 than 5 cm. long. 



Leaf-blades pubescent, at least below. 

 Stems very slender, weak : stem- 

 leaves light green, thin, spread- 

 ing, usually less than 2 cm. long. 

 Upper surface of the blades pubes- 

 cent with very long weak 

 hairs. 



Upper surface of the blades gla- 

 brous. 

 Stem stouter: stem-leaves grayish 



green, firm, 2-3 cm. long. 

 Ligule of hairs 2-4 mm. long. 



Leaf- blades glabrous on the lower surface. 

 Plant bright green : panicle broadly ovoid, 



its branches spreading. 

 Plant grayish green, the leaves purplish : 

 panicle oblong, its branches ascend- 

 ing or nearly erect. 

 Leaf-blades pubescent beneath with short 



hairs. 

 Stems slender, glabrous. 



Plant bright green : sheath margin cili- 



ate with long hairs. 

 Plant grayish green: sheath margin 



naked. 



Stems rather stout, the lower portion 

 densely pubescent with long nearly 

 erect hairs. 

 3|Spikelets exceeding 2 mm. in length. 



Primary leaf-blades elongated, broadly linear, often 



2 dm. long and 1.5 cm. wide, spreading. 

 Primary leaf-blades lanceolate : 

 Rounded or truncate at the base. 



Margins ciliate, at least for the lower half. 

 Margins naked, or sometimes with a few hairs 



at the very base. 

 Leaf-blades spreading : first scale % as long 



as the spikelet, acute. 

 Stems puberulent: primary leaf-blades 

 less than 4 cm. long : plant usually 

 purplish. 

 Stems glabrous : primary leaf-blades 5-7 



cm. long: plant usually green. 

 Leaf- blades erect : first scale K-% as long as 



the spikelet, rounded at the apex. 

 Cordate at the clasping base. 



Leaf-blades glabrous, sometimes ciliate on the 



margins. 

 Stems puberulent : blades naked on the 



margin. 



Stems glabrous : blades ciliate on the margin. 

 Leaf-blades pubescent, 

 ft Leaf-sheaths pubescent with long hairs. 



Spikelets very strongly and sharply nerved, acute : leaf-blades 

 elongated, broadly linear or 'linear-lanceolate, the larger 

 ones often 2 dm. long and 1 cm. wide. 



67. P. Wrightianum. 



91. P. erecUJolinin. 



89. P. sphaerocat-pon. 



90. P. inflatuni. 



73. P. alboman/inatum. 



74. P. tnfoliwu. 



71. P. gracilicaule. 



72. P. flavovirens. 



70. P. Ciithbertil. 

 69. P. ensifolium. 



75. P. glabrissiiituin. 



81. P. nitidum. 

 77. P. paucipiltirn. 



81. P. nitidum. 



76. P. lonffiligulatum. 



80. P. parvispicidum . 

 107. P. equilaterale. 

 52. P. Nashianuin. 



53. P. patentifolium. 

 101. P. epittfolium. 



54. P. Webber fan um. 



108. P. Ashci. 



111. P. commutattim. 



109. P. ovale. 



105. P. scabriusculum. 



