[ 237 ] 162 



JUNCAGINACE.E. 



Triglochin maritimum, (Linn.) Saline sandy places in the prairies about 

 Shayen-oju river and Devil's lake ; July 17 — fl. and fr. 



FLUVIALES. 



Potamogeton natans. (Linn.) Ponds, Upper Missouri ; July 20— /r. 

 Potamogeion juctinatus, (Linn.) Ponds near Jacques river ; July 8. 

 Potamog€to7i granwieiis, (Lmn.l) With the preceding. Specimens im- 

 perfect. 



ARACEiE. 



Arum triphyllum, (Linn.) Fertile woods, Upper Missouri ; April 28. 

 Sparganium ramosum,, (Linn.) Near Jacques river ; July 6— /r. 



JUNCACE^. 



jhinciis hufonius, (Linn.) Muddy banks of Jacques river; July 18. 

 Juncvs tenuis, (Willd.)— (small var.) Devil's lake ; August 6— /r. 

 Juncus polt/cephalus, (Michx.) With the preceding. 

 Juncus acuminatus, (Michx.) With the preceding. 



COMMELINACEiE. 



Tradescantia Virginica, (Linn.) Sandy fertile places in the valley of the 

 Missouri ; June 16. 



ALISMACE/B. 



Alisma Geyeri, (new species.) Stemless ; leaves elliptical-lanceolate, very 

 acute, attenuate at the base; flowers hexandrous. Muddy margins of 

 ponds near Devil's lake; August 6—Jl. and fr. Plant about six inches 

 high ; leaves five nerved ; lamina 3—4 inches in length, longer than 

 the petiole ; scapes, several from one root, assurgent, shorter than the 

 leaves ; the branches verticillate ; pedicles umbellate at the summit of 

 the branches ; flowers hermaphrodite, as large as in A. plafitago; 

 sepals ovate, obtuse, concave, greenish in the middle, scarious on the 

 margin ; petals roundish, white; stamens, 6; anthers roundish ; ovaries, 

 about 15, disposed in a circle, not costate, with a very short beak. Al- 

 lied to A. tenellum, (Mart. ;) but that species differs in its linear lance- 

 olate leaves, enneandrous flowers, and costate fruit. 



CYPERACEiE. 



ijyperus Schweiniizii, (Torr.) Sandy plains near Devil's lake, and prai- 

 ries of the Lower St. Peter's river ; July 28. 



Dulichiiim spathaceum, (Pers.) Swamps in the Sioux country; Octo- 

 ber— /r. 



Scispvs atrovirens, (Muhl.) With the preceding ; July 24. 



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