316 RYDBERG: STUDIES ON THE RocKy MOUNTAIN FLORA 
’ Arenaria cephaloidea sp. nov. 
Somewhat cespitose perennial; stem strict, 2-4 dm. high, 
glabrous; leaves glabrous, erect, filiform-subulate, 3-10 cm. long; 
flowers in dense headlike cymes; bracts lanceolate, often I em. 
long, scarious except the thick midrib, scabrous-ciliolate; sepals 
similar or somewhat broader, 4-5 mm. long; petals oblong, about 
half longer than the sepals. 
This is related to A. congesta Nutt. but differs in its narrower 
bracts, which are wholly scarious, except the midrib, and scabrous- 
ciliolate on the margins; also in its larger flowers, stricter stem, 
and less cespitose base. 
WASHINGTON: Spokane, Sept. 10, 1902, O. Kreager 617 (type, 
in herb. N. Y. Bot. Garden); Clark Springs, July 17, 1902, 
Kreager 100; Loon Lake, July 20, 1897, J. B. Winston; Spokane 
County, June 27, 1884, Suksdorf. 
Ipano: Lake Coeur d’Alene, June and July 1892, G. B. Aiton; 
Little Potlatch River, June 2, 1892, Sandberg, MacDougal & Heller | 
478. 
, Arenaria lithophila Rydb. comb. nov. 
Arenaria subcongesta lithophila Rydb. Mem. N. Y. Bot. Gard. 1: 
148. 1900. 
This, I think, deserves specific rank. Some of the specimens 
recorded as A, subcongesta (S. Wats.) Rydb. should also be referred 
to it. | 
‘Alsinopsis dawsonensis (Britt.) Rydb. comb. nov. 
Arenaria dawsonensis Britt. Bull. N. Y. Bot. Gard. 2: 169. oo 
This species has been collected in the Black Hills of Sout 
Dakota. 
* Alsinopsis pusilla (S. Wats.) Rydb. comb. nov. 
Arenaria pusilla S. Wats. Proc. Am. Acad. 17: 367. 1882. 
This species has been collected in Idaho. 
~ Arenaria laxiflora nom. nov. 
Arenaria Fendleri diffusa Porter, Syn. Fl. Colo. 13- 
A, diffusa Ell. 1818. 
