[Vor. 5 
90 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
193. S. На! Britton, Trans. N. Y. Acad. Sci. 9 : 11. 1889; 
Rydb. Mem. N. Y. Bot. Gard. 1 : 445. 1900. Pl. 4, fig. 2. 
A low cespitose herbaceous perennial, densely and conspicu- 
ously white-tomentose throughout; stems erect, 1 to 1.8 dm. 
high, simple or branched; basal and lower stem-leaves spatu- 
late to oblanceolate, 1.5 to 5 em. long, 4 to 10 mm. broad, 
densely and permanently white-tomentose on both surfaces, 
rounded to obtuse at the apex, entire, often revolute-margined, 
narrowed into a petiole about equalling the blade; upper stem- 
leaves few, sessile, lanceolate, and often somewhat ampliated 
into an entire or toothed semiamplexicaul base; inflorescence 
a terminal few to several-headed corymbose cyme; heads 8 
to 10 mm. high, radiate; involucre campanulate, sparingly 
ealyeulate; bracts of the involucre about 13, linear-lanceolate, 
5 to 6 mm. long, at first densely white-tomentose, later more 
or less glabrate; ray-flowers 8, rays pale yellow; disk-flowers 
about 30; achenes glabrous. 
Distribution: known only from geyser formations of Yel- 
lowstone National Park. 
Specimens examined: 
Yellowstone National Park: on geyserite, June, 1888, Rev. 
Dr. Charles H. Hall (N. Y. Bot. Gard. Herb. and Greene Herb., 
Univ. of Notre Dame), түре; directly on geyserite, Shoshone 
Geyser Basin, alt. 2375 m., 23-26 Aug., “С. В.” (Gray Herb.) ; 
National Park, alt. 2438 m., 3 Aug., 1885, Letterman 259 
(Mo. Bot. Gard. Herb.) ; Upper Geyser Basin, alt. about 2135 
m., 8 Aug., 1897, Rydberg Ф Bessey 5257 (Gray Herb., Greene 
Herb., Univ. of Notre Dame, Mont. Agr. Coll. Herb., and U. 
S. Nat. Herb.) ; Mammoth Hot Springs, 5 July, 1899, Blankin- 
ship (Gray Herb.) ; Upper Geyser Basin, 12 July, 1899, Blan- 
kinship (Gray Herb.); Lower Geyser Basin, 13 July, 1899, 
Blankinship (Gray Herb.) ; without definite locality, 16 Sept., 
1902, Mearns 4059 (U. S. Nat. Herb.) ; Upper Basin, 17 July, 
1912, Churchill (J. R. Churchill Herb.). 
124. S.candidissimus Greene, Pittonia 4: 110. 1900. 
An herbaceous perennial, densely and permanently white- 
tomentose throughout; stems ascending or suberect, 1.5 to 2.5 
