New Plants from Wyoming.— Y* 



By Aven Nelson 



Scirpus paludosus 



Perennial from corm-like tubers, which bear short^horizontal 

 rootstocks that produce terminally other propagative tubers : culms 

 moderately stout, erect, 4-8 dm. high, triangular, the two faces 

 plane, the other narrower and somewhat grooved : leaves pale 

 green, often equalling or even exceeding the culms, 5-8 mm. wide, 

 glabrous, longitudinally nerve-grooved (11-25 nervures) : invo- 

 lucral leaves 2 (possibly rarely 3). both much exceeding the inflo- 

 rescence, the shorter from 5-10 cm. long, the other twice or thrice 

 as long : spikelets 3 to several in a dense, terminal head, ovate or 



mm. long, 6-10 mm. in diameter: scales narrowly 



0-20 



ovate, membranous, puberulent, light brown, two-toothed at apex. 

 the midrib prolonged into an awn about one-fourth as long as the 

 scale ; bristles usually 2, twice the length of the akene ; style 

 about 8 mm. long, two-cleft for less than half its length ; akene 

 lenticular, broadly obovate, nearly 3 mm. long, tipped with a con- 

 ical tooth, brown, the surface shiny, finely pitted under a lens. 



This species is probably most 



camp 



Britton, from which it is clearly separated by its remarkable tubers 

 (subspherical, 10-2$ mm. in diameter), to say 



nothing of the 



minor characters given in the description. It is a plant that thrives 

 in the most pronounced saline soils. The first specimens were se- 

 cured on Salt Creek, near Newcastle, July 30, 1896, but it seems 

 to occur in all the strongly alkaline marshes in the southern part 

 of the state as well. The best specimens were secured at 

 Granger, Sweetwater County, from the salt-encrusted bed of a dry 

 pond where it was absolutely the only vegetation. Some of the 

 soil (?), where it was growing, was taken for analysis and found to 

 contain more than 60^ of soluble salts. 



Type specimen in Herbarium University of Wyoming, no. 



J 



1897, 



Collected also on the Laramie 



Plains in the margins of the Soda Lakes that occur at intervals. 

 The tubers are never absent ; the growth is often luxuriant and 

 where it is accessible cattle eat it with avidity. 



Professor Nelson has generously deposited cotypes of these plants in the herbarium 



of Columbia University. — Ed. 



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