120 



GRAMINEAE (gKASS FAMILY) 



1. Z. paliistris L, (Indian Rice, Water Oats.) Annual ; cnlms 2-3 m. 

 high ; leaves flat, 5-10 dm. long, 1.5-4c m. wide. (Z. aqnatica of aiuh. not L.) — 

 Swampy border.s of .streams and in shallow water ; common, 

 especially northwe.stw. July, Aug. (Asia.) Fig. 73. 



2. Z. aquatica L. Culms about 1 in. hiirh ; leaves nar- 

 rower (less than 1 cm. wide) ; pistillate jjurtion of panicle 

 more appressed. — Me, to Minn., and northw. 



17. ZIZANIOPSIS Doll & Asch. 



Spikelets unisexual, the pistillate above, the staminate below 

 on each branch of the panicle, much alike in appearance^ 

 laterally compressed ; glumes subequal, membranaceous, the 

 first glume of the pistillate spikelet with a short terminal awn, 

 the lemma acute, palea none ; glumes and lemma of staminate 

 spikelet acute, nerveless, palea none ; stamens 6 ; grain ovoid, 

 with a chartaceous easily separable pericarp, loosely inclosed 

 in the glumes. — A tall aquatic grass with long leaves and 

 long narrow terminal panicles. (Xame from Zizania and 

 6-(/'ts. appearance, from likeness to the preceding genus.) 

 1. Z. miliacea (Michx.) Doll & Asch. Perennial by a creeping rootstock ; 

 culms 1-4 m. high, geniculate at the lower nodes; leaves flat, 3-10 dm. long, 

 1-3 cm. wide. {Zizania Michx.) — Swamps, Va., O., and southw. May. 



vii 



73. Z. aquatica x 1 

 ^ spikelet. 

 9 spikelet. 

 Pistil with scales. 



18. LEERSIA Sw. Cut-grass. White Grass 



Spikelets 1-flowered, flattened laterally, perfect, but those in the open panicles 

 usually sterile, those inclosed in the sheaths cleistogamous and fruitful ; glumes 

 none, lemma boat-shaped, somewhat indurated, awnless, 

 clasping the palea by a pair of strong marginal nerves ; palea 

 of like texture, much narrower, 1-nerved ; stamens 1-6. — 

 Perennials of moist ground, with rough leaves and short 

 racemes of imbricated spikelets arranged in open panicles. 

 (Named after Johann Daniel Leers, a German botanist of 

 the 18th century.) Homalocexchrus Mieg. 



* Spikelets narrowly ohlong, rather loosely crowded. 



I 



74. L. virginica. 

 A bit of intiorescence 



x3. 

 Spikelet x 5. 



1. L. virginica Willd. (White Grass.) Culms weak, 

 branched, ascending, with clustered scaly rootstocks ; panicle 

 simple, the slender branches stiffly spread- 

 ing ; spikelets 2.5-3 mm. lone/, closely ap- 

 pressed ; lemma hispid on the keel ; stamens 

 2. — Wet woods, Me. to Ont., and southw. 

 Aug. Fig. 74. 



2. L. oryzoides (L.) Sw. (Rice Cit-grass.) Culms rather 

 stout, braii(ii('(l, a.scending from a decumbent base with slender 

 creepiiKj rootstocks- leaves very ronr/h ,' panicle diffusely 

 branched, lax ; spikelets 4-5 mm. lomj ; lemma hispid, strongly 

 bristly ciliate on the keel. — Swamps or stream borders, ditches, 

 etc., Nfd. to Ont., and southw. Aug., Sept. (S. A., Eurasia.) 

 Fig. 75. 



75. L. oryzoides. 

 Inflorescence x Vn- 

 A bit of same x 2^. 

 Open spikelet x 'J. 



* * Spikelets broadly oval, imbricately covering each other. 



o 

 •J. 



L. lenticularis Michx. (Catch-fly Grass.) Culms 

 nearly simple, erect or decumbent at base, with scaly root- 

 stocks ; sheaths and blades sometimes nearly smooth ; panicle 

 ne;irly simple ; spikelets very flat, 5 mm. long, strongly bristly 



ciliate. — Low groun<ls, Va. to Minn., and .southw. 



