282 PITTONIA. 
11281); Spence's Bridge, B. C., Macoun, n. 11282; summit 
of Mt. Arrowsmith, Vancouver Island, Macoun, n. 11279; 
pine woods near Spokane, Washington, C. V. Piper, n. 
2273; Mt. Hood, Oregon, Thos. Howell; Crooked Creek, 
southeastern Oregon, and Warner Range, northeastern Cal- 
ifornia, Mrs. Austin. 
A. APRICA. Cespitose, stout and low, the stolons short, 
ascending, crowded and leafy: cuneate-oblanceolate acutish 
leaves less than an inch long, rather densely silvery-tomentose 
on both faces; stems usually about 3 inches high, leafy- 
bracted, the bracts suberect, narrow, very acute, more than 
4 inch long; heads 3 to 6, large for the plant, sessile or the 
pedicels very short; bracts of the involucre much imbricated 
in rather numerous series, all with short woolly base, the 
rather dull-white or creamy tips very unequal, those of the 
outer series very short and obtuse, of the others successively 
longer, passing from obovate to oblong and oblong-lanceo- 
late, and from obtuse or almost truncate to acutish, or some 
tridentate, all more or less distinctly and evenly serrulate. 
Very common species of the whole Rocky Mountain 
region, southward (in Colorado) preferring sunny exposures 
among foothills, but in British America occupying the dry 
open prairies. Apparently taken by Mr. Rydberg for the 
real A. dioica, to which, however, A. parvifolia is far more 
nearly allied. It has been obtained in Colorado by many 
collectors. In Utah, at Alta, by M. E. Jones, 1886. Cen- 
tennial Valley, Wyoming, A. Nelson, 1895, n. 1269. Yel- 
lowstone Park, F. H. Burglehaus, 1893. Then along its 
eastern limits, by Geyer, on dry hills of the Missouri, 1839. 
Middle Loup River, Rydberg, 1883, n. 1292, and by the same 
near Lead City, South Dakota, 1892, n.793. Farther to the 
westward, by R. S. Williams, at Columbia Falls, Montana, 
1894; and in the Canadian Survey collection as follows. 
Open prairies, Brandon, Manitoba, by Macoun, 1896, D. 
12439. Prairies of White Mud River, Assiniboia, by the : 
