Hitchcock — The (inisscs of fldwaii 143 



1. Avena sativa I.. Sji. I'l. 79. 1753. Crr.ri\ATi;i) uat. 



Similar to .1. faliia: tlorets not readily sejiarating from tlic glumes, spikelets commonly 

 2-flo\.erc(l : lemma glabrous: awn straight, or wanting. 



Occasional in waste places, mostly as a waif. Orijrinally described from 

 cultivated plants in Europe. 

 Oaliu : Schoficld Barracks, Tlitclicnck 13972. 



2. Avena fatua L. Sp. PI. So. 1753. W'u.u o.\t. 



Plants annual: culms 30 to 90 cm. tall, erect, stout: ]janicle loose and (jpen. the slender 

 liranches as a rule horizontally spreading: spikelets commonly 3-tiowered : glumes alxiut 2.5 cm. 

 long: rachilla and lower part of shining lemma clothed with long stiff brownish hairs; florets 

 readily falling from the glumes: lemma nerved above, alxiut 2 cm. long, the teeth acuminate Init 

 not awned : awn stout, geniculate, red-brown, twisted below, about 3 cm. long (fig. 28). 



\\^cc(l along roadside; introduced. (Jriginally deseriljcd from Europe. 

 Oahu: Xuuanu Pali, Hitchcock 13749. 



3. Avena barbata P-rot, Fl. Lusit. i :io8. 1804. 



Dififers from A. fatua in having somewhat smaller, 2-flow'ered spikelets. with curved anrl 

 capillarv pedicels : teeth of lemma ending in fine awns 2 mm. long. 



^^'eed along road ; introduced. Originally described from Europe. 

 Oahu: Schofield Barracks, Hitchcock 13034. 



T4. ARRHENATHERUM Beauv. 



Spikelets 2-flowered, the lower floret staminate, the upper perfect, the rachilla disarticu- 

 lating al)ove the glumes, produced beyond the florets as a slender bristle : glumes rather broad 

 and papery, the first i-nerved, the second a little longer than the first and about as long as the 

 spikelet, 3-nerved : lemmas 5-nerved, hairy on the callus, the lower bearing near the base a 

 twisted, geniculate, exserted awn, the upper bearing a short straight, slender awn just below 

 the tip. Perennial, rather tall grasses, with flat blades and rather dense panicles. 



1. Arrhenatherum elatius (L.) Beauv. : Mert. & Koch in Rohl, Deutsch. Fl. i :546. 1823. T.\ll 



MEADOW OAT GRASS. 



Avena elatior L. Sp. PI. 79. 1753. 



Arrhcnathcrnni avenacciim Beauv. Ess. Agrost. 132, pi. 11, f. 5. 1812. 



Culms a meter or more tall: blades as much as i cm. wide, scabrous on both surfaces; 

 panicle pale or purplish, shining, 15 to 30 cm. long, narrow, the short branches verticillate, usuallv 

 spikelet-bcaring from the base ; spikelets 7 to 8 mm. long : glumes minutely scabrous, the second 

 about equaling the florets ; lemmas scabrous, the awn of the staminate floret about twice the 

 length of its lemma; palea as long as the lemma (fig. 29). 



Pasture land at medium altitudes. Cultivated as a jiasture grass and estab- 

 lished here and there. Originally described from Europe. 

 Hawaii: Kukaiau Ranch, Plitchcock 14267. 



15. AIRA L. 



Spikelets 2-flowered, disarticulating above the glumes, the hairy rachilla prolonged behind 

 the upper floret as a stipe, this in some plants bearing a reduced floret : glumes alx)ut equal, 

 acute or acutish, membranaceous ; lemmas thin, truncate and 2 to 4-toothed at the summit, bear- 

 ing a slender awn from or below the middle, the awn straight, bent or twisted. Low or moder- 

 ately tall annual or commonly peremiial grasses, with shining pale or purplis^h spikelets in narrow 

 or open panicles. 



Us J 



