Hitchcock — 'I'lic (.,'rasscs of Hawaii iij 



S\vaiTi])y ground: introduced. Originally described from Europe. Prob- 

 ably introduced with gras.s seed; other European meadow grasses are nearby. 

 Maui: Haleakala crater, west side, about 6000 feet, Hitchcock 1499''). 



:)• 



POA ].. 



Spikelets 2 to several-flowered, the rachilla disarticiilating" alxn'e the tjlunies and between 

 the florets, the uppermost floret rechiced or rudimentary; glumes acute, keeled, somewhat unequal, 

 the first i-nerved, the second commonl}' 3-ncrved ; lemmas somewhat keeled, acute or acutish, 

 awnless, mem])ranaceous, many somewhat scarious at the tip, 5-nerved, the nerves pubescent in 

 .some species. Annual, or usually perennial, species of low or rather tall grasses, with spikelets in 

 open or contracted panicles, the narrow blades flat or folded, ending in a navicular point. 



Plants annual: nerves of lemma villous i. P. annua. 



Plants perennial ; nerves pubescent or glalirous. 

 Creeping rhizomes present ; sheaths open. 



Culms much flattened : lemmas obscurely nerved 2. P. compressa. 



Culms scarcely flattened : lemmas rather strongly 5-nerved 3. P. pratensis. 



Creeping rhizomes absent ; sheaths closed. 



Ligule deeply fimbriate 4. P. mannii. 



Ligule entire or dentate, not deeply fimbriate. 



Old culms as much as 3 or 4 meters long, rushlike, bearing bladeless sheaths 



5. P. siphonoglossa. 



Old culms not becoming elongate, leafless, and rushlike 6. P. sandvicensis. 



1. Poa annua L. Sp. PI. 68. 1753. Annu.\l blue gr.\ss. 



Plants annual ; culms flattened, decumbent at base, some rooting at the lower nodes, 10 to 

 30 cm. tall ; sheaths loose ; blades soft and la.x ; panicle pyramidal, open, 2 to 6 cm. long ; spike- 

 lets crowded, 3 to 6-flowered, about 4 mm. long ; lemma not webbed at base, distinctly 5-nerved, 

 the nerves villous on the lower half (fig. 6). 



A weed in open ground, mostly at upper elevations ; introduced. Originally 

 described from Europe. 



Oahu: Nuuanu Pali, Hitchcock 13750, 13782. 



Maui: Olinda pipe line, Hitchcock 14922. Ulupalakua, East Maui, Mann 

 & Brigham 459. 



Hawaii: Puu Oo, Forbes 863. Kukaiau Ranch, Plitchcock 14223, 14269. Mauna 

 Kea, near lake, Hitchcock 14455. Without locality, Wilkes Expl. Exped. 

 Without locality: Hillebrand. 



2. Poa compressa L. Sp. PI. 69. 1753. C.\n.\d.v bluk gr.vss. 



Plants perennial, with creeping rhizomes: culms scattered, not tufted, geniculate-ascending, 

 flattened, wiry, bluish green, 15 to 40 cm. tall; panicle narrow, 2 to 7 cm. long, the commonly 

 short branches in pairs, spikelet-bearing to the base ; .spikelets crowded, subsessile, 3 to 6-flo\v- 

 ered, 4 to 6 mm. long; glumes about 2 mm. long, 3-nerved ; lemmas firm, obscurely nerved,. 

 2 to 2.5 mm. long, sparingly webbed at base, short-pubescent below on the keel and 'marginal 

 nerves (fig. 5). 



Moist places; introduced. Originally described from Europe and North 

 America. 



Hawaii: Around water tank on way to Humuula Sheep Station, Hitchcock 14442. 



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