42 LEAFLETS. 



lanceolate, acuminate, 5 to 8 inches long, IJ to 2 inches broad, 

 spreading, sparsely scaberulous above, the lower face, and espe- 

 cially the midvein, rough with short rigid acute closely appressed 

 hairs; petioles an inch long or more; sheaths clothed with long 

 closely appressed bristly hairs, the summit somewhat lacerate 

 and bristly-ciliate : spikes several, long, linear, somewhat droop- 

 ing : achenes thick-lenticular, not highly polished but rather 

 dull blackish. 



Swamps along the Mississippi near its mouth in extreme 

 southern Louisiana, 18 July, 1885, Kev. A. B. Langlois. A tall 

 and rank member of this group, with long, half -drooping spikes. 

 Aquatic and floating form to be sought. 



P. CusiCKii. Eather slender upright amply leafy stems two 

 feet high or more from a prostrate and submersed rooting por- 

 tion quite as slender, both the submersed and aerial internodes 

 about 3 inches long, the aerial nodes abruptly swollen and the 

 whole stem strongly striate, glabrous: blades of the short- 

 petioled and spreading leaves 5 to 8 inches long, oblong-lanceo- 

 late, acuminate, thin, slightly undulate, inconspicuously and 

 finely appressed-pubescent on both faces, only the stout closely 

 appressed hairs of the midvein beneath with a thick base : ocrese 

 hyaline, clothed with long soft appressed hairs; peduncles 

 glandular-hispid, 2 J inches long, the cylindric spikes narrow 

 and about as long, the whole not equalling the upper leaves ; 

 bracts with long appressed dorsal and margined hairs, and 

 some shorter gland-tipped ones at base. 



Tules of the Grand Rond Valley, eastern Oregon, Aug., 1897, 

 W. 0. Cusick ; the type in my herbarium under the collector's 

 n. 1764. Evidently here, as in the case of P. rigidula of the 

 upper Missouri region, we have a species truly aquatic, as to 

 the basal parts and the roots, but with still the habit, foliage, 

 and inflorescence of the strictly terrestrial species. 



I refer to P. Cusickii various sheets collected in eastern Ore- 

 gon, "Washington, and Idaho, by Suksdorf, Leiberg, Sandberg, 

 Elmer and others. 



P. EkakciscanA. Terrestrial state erect, densely leafy, % 

 feet high, the nodes not swollen, internodes about 2 inches long. 



