[ 237 ] 164 



Mvhletibergia glomeraia, (Trin.) Prairie?, Upper Missouri ; July 13. 

 Miihletihngia ambigva, (new species) Panicle dense, opiciform; glumes 

 rather unequal, (the inferior one shorter;) linear lanceolate, very acute, 

 I — 2 flowered ; very hairy at the base; superior valve, with a bristle 

 at the lip equalling it in length, a little shorter than the glumes, (ex- 

 clusive of the awns;) superior floret, either perfect, and then resem- 

 blitig the inferior or rudimentary and aristiform. Stony banks of 

 Okaman lake, Sioux country, September 20. Culms cespitose, about 

 1^ foot high, glabrous; leaves broadly linear; stipules very short, 

 truncate and lacerate; panicle 4 — 6 inches long; purplish; glumes 

 tapering to a very acute cuspidate point, with a strong green midrib ; 

 perianth clothed at the base with whitish hairs, which are nearly half 

 as long as the valves ; valves nearly equal ; awn a little tortuous, 

 sometimes longer than the valve ; superior floret often perfect, and 

 maturing its fruit ; when rudimentary, consisting of a mere awn, with- 

 out any valve. A remarkable species, with the habit of M. glomeraia 

 and M. Mexicana. 



Vilfa cuspidata, (Torr., in Hook. Fl. Bor. Amer. 2, p. 238 ) Hills of the 

 Missouri, near White river, and about Devil's lake; June IG— July 20. 



Vilfa heterolepis, (Gray, in Ann. Lye, New York, 4, p. 233.) Banks of 

 Shaven river ; August 12. 



Agrostis Michavxii, (Trin.) Prairies between Jacques and Shayen rivers; 

 abundant ; July 6. 



Agrostis crypiandra^ (Torr., in Ann. Lye. New York, 1, p. 151.) Banks 

 of Spirit lake, Little Sioux river, &c. ; September 30. 



Caiamagrostis stricia, (Null.) Dry swamps in the prairie of Shayen 

 river ; July 26. 



Caiamagrostis longifolia, (Hook., Fl. Bor. Amer., 2, p. 241.) Sandy plains 

 and dry swamps, Jacques river ; July 3. 



Arundo phrag mites, (Linn.) Common in all wet prairies and swamps be- 

 tween the Missouri and Mississippi rivers ; July 26. 



Spartina cynosiiroides, (Willd.) Common in wet prairies ; July 26. 



Aristida pollens, (Nutt.) Arid situations, Upper Missouri ; July 4 — 24. 



Poa airoides, (Nutt.) Saline borders of Devil's lake ; abundant ; August 1. 



Poa nemoralis, (Linn.) Shady woods and ravines, on the Missouri ; June 6. 



Poa crocato, (Michx.) Prairies of Devil's lake, &.c.; July 18. 



Poa eragrosiis, (Linn.) Sandy plains, valley of the Shayenoju river ; 

 July 27. 



Catabrosa aqnatica., (P. de Beau v.) Swamps, Devil's lake ; July 31. 



Koileria cristaia, (Pers.) High sandy prairies on the Missouri and Upper 

 St. Peter's rivers ; July 12. 



Festuca tenella, (Willd.) Valley of the Upper Missouri ; June 20. 



Br omiis purgans, (Linn.) Borders of woods ; July 26. 



Glyceria aquafica, (Smith, Trin.) Swamps about Devil's lake ; July 30. 



Glycerin nervata, (Trin. in Act. Petrop., 6. sec. 1, p. 365.) J^oa nervata, 

 (Willd.) With the preceding. 



Glyceria Jluitans, (R. Br.) With the preceding. 



Vniola stricta, (Torr. in Ann. Lye. New York, 1, p. 55.) Brizopyrum 

 spicatu7n, (Hook., and Am. Bot. Beech, p. 403, and Hook Fl. Bor. 

 Amer., 2, p. 254, in part?) Hills of the Upper Missouri, June 1. I can 

 hardly agree with my friend, Sir William Hooker, in regarding this 

 plant as a form of the ordinary U. sjiicata, so common on the Atlan- 

 tic coast of the United States. 



