520 Wiegand: Juncus tenuis Willd. 



equaling the filament : styles short (.5 mm. long): capsule firm, 

 rather narrowly oblong, triangular above, obtuse or retuse, equal- 

 ing the perianth ; placentae completely meeting at the axis : seeds 

 quite large, oblong (. 5—. 5 5 x .2 mm.) rather slender and strongly, 

 often obliquely, apiculate at each end, areolate. 



Arkansas to Idaho. 



Specimens examined : 



Arkansas : (Between Morka and Red Fork) (Marcy's Ex- 

 ped. Herb. G. Thurber); Upper Platte (Hayden in Gray Herb. type). 



Idaho: (Lake Waha) (Heller, no. 3410, 1896). 



The limited material of this species makes its range rather 

 doubtful. It is closely related to Juncus confusus in flower and 

 fruit characters, indeed differs from that species only in its more 

 acute perianth segments, more open paler inflorescence, and es- 

 pecially in the stout culm and short broad leaves. It differs from 

 /. interior in the large scarious auricles and larger perianth. 



9. Juncus confusus Coville, Proc. Biol. Soc. Wash. 10 : 127. 



1896 



Strict but slender, 4-5 dm. high, erect, light green : culms mod- 

 erately grooved, sparingly tufted : leaves very narrow, nearly fili- 

 form, two thirds the length of the culm or less, flat and unusually 

 thick, commonly also involute ; sheaths short, narrow, close, some 

 of the lower bladeless and looser, yellowish-white, margins and 

 produced auricles scarious, the latter whitish : inflorescence very 

 short, compact, capitate (. 5-2 cm. long), pale fuscous ; bract 2-7 cm. 

 long, filiform, exceeding the inflorescence ; bracteoles large, ovate, 

 scarious, obtuse or acutish : perianth small (3.5-4 mm. long), the 

 parts nearly equal, appressed, lanceolate, acutish, stramineous with 

 a fuscous stripe on each side, margins all rather broadly scarious 

 to the apex : stamens one-half the length of the perianth : anthers 

 oblong, shorter than the filament : styles quite short : capsule firm, 

 oblong, a little shorter than the perianth, conspicuously triangular 

 and retuse at the apex, placentae completely meeting at the axis : 

 seeds large, oblong, apiculate and often oblique at the ends (.45"" 

 .50 x .2 mm.), coarsely and shallowly areolate. 



Colorado to Montana and possibly Idaho. 



Specimens examined : 



Colorado : (Hall and Harbour), Chicken Creek (Baker, Earle 



and Tracy, no. 742, 1898). 



Wv 



(A. Nelson, no. 163 1). 



400 



