GRAMINEAE (GRASS FAMILY) 



141 



* Spikelets more than 2 cm. long ; annuals. 



1. A. FATUA L. Culms 4-12 dm. high, in small tufts, erect, stout ; blades 

 long, 5-8 mm. wide ; panicle loose and open, the slender branches ascending ; 

 spikelets pe7uhilons, 2,2-2.5 cm. long, excluding the awns ; 



(jlumts smooth, striate, acuminate ; florets approximate ; 

 lemmas with a ring of hairs at base and more or less 

 appressed-pubescent with long stiff brownish hairs; awn 

 inserted about the middle, bent and twisied, 3 cm. long 

 or more. — Fields and waste places, Ont. and 0. (rare) ; 

 Wise, 111., and westw. (Nat. from Eu.) Fig. 124. 



2. A. STERiLis L. (Animated Oats.) Larger than 

 the preceding, the spikelets 3.5-4.5 cm. long, excluding 

 the awns ; lemmas usually more densely hairy ; awns 

 5-7 cm. long. — Occurs sparingly, in N. J. and near Phila- 

 delphia, Pa. (Adv. from Eu.) 



A. SATivA L., the cultivated oat, commonly occurs in 

 waste places in cities, etc. (Introd. from Eurasia.) 



* * Spikelets less than 1.5 cm. long ; perennials. 



124. A. fatua. 

 Spikelet x %. 



3. A. puBESCExs Huds. Culms 6-9 cm. high, in small tufts, erect, slender ; 

 sheaths and blades, at least the lower, retrorsely pubescent ; panicle rather nar- 

 row, the slender flexuous branches erect; spikelets upright, 1.2-1.3 cm. long, 

 excluding the awns ; glumes S-nerved, the nerves scabrous ; florets approximate, 

 rhachilla-joints clothed with long white hairs ; lemmas scabrous, a tuft of ichite 

 hairs at the base, a bent and twisted awn inserted about the middle, 2-2.5 mm. 

 long. — Fields, Vt., N. J. (Adv. from Eu.) 



46. ARRHENATHERUM Beauv. Oat Grass 



Spikelets 2-flowered, the florets approximate, the lower staminate, its lemma 

 bearing a geniculate and twisted awn on the back near the base ; the upper per- 

 fect, its lemma short-awned from or near the apex, or awnless ; rhachilla hairy, 

 prolonged behind the upper palea into a bristle ; glumes unequal, acute, thin 



and scarious ; lemmas of firmer texture, 5-7-nerved ; palea 

 ciliate on the nerves. — Tall perennials with flat leaves and 

 long narrow panicles. (Name from dppvv, masculine, and 

 dd-np, awn, in reference to the awned staminate floret.) 



1. A. elXtius (L.) Beauv. (Tall O.) Culms 1 m. or more 

 high, erect; leaves long, linear, 0.5-1 cm. wide, scabrous on 

 both surfaces ; panicle pale or purplish and shining, 15-30 cm. 

 long, narrow, the short branches verticillate, usually spike- 

 let-bearing from the base ; spikelets 7-8 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; paleas as long as their lemmas. {A. avenaceum 

 Beauv.) — Meadows and waste places, Nfd. to Va., Ont., Minn., etc.; often 

 cultivated. June, July. (Nat. from Eu.) Fig. 125. 



125. A. elatius. 



Spikelet with glumes 



detached x 2. 



47. DANTH6nIA DC. Wild Oat Grass 



Spikelets several-flowered ; florets not closely approximate, uppermost imper- 

 fect or rudimentary ; glumes subequal, much longer than the lemmas, usually 

 exceeding the uppermost floret ; lemma convex, 2-t()otlied or bifid at the apex, 

 with a twisted awn between the teeth ; awn flat, formed by the extension of the 

 3 middle nerves of the lemma. — Tufted erect perennials with narrow leaves and 

 small terminal panicles or racemes. (Named for Etienne Danthoine, a botanist 

 of Marseilles.) 



