500 COMPOSITAE (COMPOSITE FAMILY) 



inner, oblanceolate, abruptly acute, villous: rays 10-12 mm. long, bright 

 yellow: achenes sparingly strigose-hirsute. Colorado. 



3. Pyrrocoma integrifolia (Porter) Greene, 1. c. Stems several from the 

 caudex, ascending, 1.5-2.5 dm. high: radical leaves (including short petiole 

 or tapering base) 7-15 cm. long; the cauline lanceolate, or the small uppermost 

 linear: heads solitary or 2 or 3 in the upper axils; involucral bracts narrowly 

 oblong to linear-lanceolate, some loose outer ones usually equaling the disk 

 and more foliaceous: rays bright yellow, 9-12 mm. long: ftchenes oblong. 

 Mountain meadows of Wyoming and Montana. 



4. Pyrrocoma uniflora (Hook.) Greene, 1. c. 60. Stems 1-2 dm. high, 

 ascending or erect, sometimes 5-6-leaved, sometimes rather scapiform or 

 upper leaves reduced and bract-like, bearing a solitary head, rarely 1 or 2 

 axillary: leaves lanceolate or sometimes broader; radical 5-8 cm. long and 

 usually petioled: involucre commonly 10-12 mm. high, and the linear or 

 oblong-linear bracts all of same length, rather loose, outer all foliaceous. [P. 

 inuloides (Hook.) Greene, 1. c.; P. villosa Rydb. 1. c. 625; P. acuminata Rydb. 

 1. c.] Frequent in moist saline soils; Montana to Colorado and Utah. 



5. Pyrrocoma lanceolata (Hook.) Greene, 1. c. 69. Habit of the preceding; 

 stems generally more leafy and bearing 3-15 heads; these when few subcorym- 

 bose, when more numerous racemosely or paniculately disposed: involucre 

 10-15 mm. high (the heads varying much in size) ; the bracts rather closely 

 imbricated in 3 or 4 unequal series, lanceolate, acutish, with short green tips 

 and whitish coriaceous base; outer successively shorter, occasionally some of 

 them longer and more herbaceous. [P. Vaseyi (Parry) Rydb. 1. c.; P. lagopus 

 Rydb. Bull. Torr. Bot. Club 32: 136. 1905.] Saline soils; Saskatchewan to 

 northern Colorado and west to Nevada. 



13. OONOPSIS Greene 



Plants with equably leafy upright stems, usually tufted, upon a ligneous 

 caudex or crown. Leaves entire; herbage lanate-tomentulose or glabrous. 

 Heads in a terminal fastigiate cyme or solitary, discoid or radiate. Invo- 

 lucres ovate or broader; bracts not carinate, but flat and often 3-nerved, im- 

 bricated, subcoriaceous and with green-herbaceous tips ending in a cusp. 

 Disk-corollas subcylindric, with 5 rather short teeth. Stamens and styles 

 scarcely exserted; tips of the latter ovate to subulate, shorter than the stig- 

 matic part. Achenes mostly glabrous, and pappus coarse, rigid, and rather 

 scanty. This genus is unique in that each of its species is seemingly con- 

 fined to restricted areas and is singularly limited as to habitat. Aplopappus in 

 part. 



Dwarf and somewhat caespitose, less than 1 dm. high. 

 Rays 6-10. 



Leaves short (2-3 cm.) . . . . . . . . 1. O. multicaulis. 



Leaves long (4-8 cm.) 2. O. argillacea. 



Rayless . . . . . . . . . . . 3. O. Engelmannii. 



Taller, 1-3 dm. high; stems few to many. 

 Rayless. 



Stems numerous, fascicled, branched; heads in terminal glomer- 

 ules. 



Leaves short (3-6 cm.) 4. O. Wardii. 



Leaves long (6-12 cm.) 5. O. condensata. 



Stems solitary or few; heads solitary . . . . . . 6. O. monocephala. 



Rays numerous . . . . . . . . . . 7. O. foliosa. 



1. Oonopsis multicaulis (Nutt.) Greene, Pitt. 3: 45. 1906. Very dwarf, 

 tufted, tomentulose, but early glabrate and smooth; stems 3-7 cm. high, from 

 a ligneous caudex, simple or forked, bearing 3 or 4 leaves and few heads: leaves 

 narrowly linear, or the lowest obscurely spatulate, 2-3 cm. long: bracts of 

 the involucre large and rather few (9-14), ovate to oblong-lanceolate, 

 cuspidate-acuminate, marked with a green spot below the slender cusp, or the 

 outi-rmost with a larger foliaceous tip. "On rocks, mountains of north- 

 western Wyoming." 



