380 
CARDUACEAE. 
68 . CHAMAECHAENACTIS Rydb. 
i. Chamaechaenactis scaposa (Eastw.) Rydb. (Chaenactis scaposa Eastw.) 
In arid regions of Utah and Colo.—Grand Junction. 
69. RYDBERGIA Greene. 
Involucres densely white-woolly at the base; basal leaves more or less doubly 
pinnatifid. 1. R. grandidora. 
Involucres darker, short-villous at the base; leaves simply pinnatifid with few 
divisions. 2. R. Brandegei. 
1. Rydbergia grandiflora (T. & G.) Greene. ( Actinella grandiUora T. & G.) 
On high mountain sides from Mont, to N. M. and Calif.—Alt. 9000-13,500 
ft.—Alpine Tunnel; Pike’s Peak; Ironton, San Juan Co.; Gray’s Peak; 
Mt. Harvard; Mt. Abram, Ouray; Seven Lakes; mountains south of Ward, 
Boulder Co.; Little Kate Mine, La Plata Mountains; near Pagosa Peak; 
Floral Mountain, near Georgetown; mountains above Como; Carson; Cam¬ 
eron Pass; Berthoud Pass; Beaver Creek; mountain northwest of Como; 
mountains about Graymont; Massif de l’Arapahoe; Hinsdale Co.; headwaters 
of Clear Creek; Ethel Peak. 
2. Rydbergia Brandegei (A. Gray) Rydb. ( Actinella Brandegei A. Gray; 
Rydbergia glabrata Greene) On high peaks of southern Colo, and N. M.— 
Alt. 9000-13,000 ft. — West Spanish Peak; Sierra Blanca. 
70. HYMENOXYS Cass. Colorado Rubber Plant. 
1. H. macrantha. 
2. H. pumila. 
Plant low, perennial with a multicipal caudex. 
Heads mostly solitary at the ends of the branches. 
Rays 12-18 mm. long; plant 1-3 dm. high. 
Rays 5-8 mm. long; plant less than 1 dm. high. 
Heads mostly corymbose. 
Rays orange, broadly cuneate. 3. H. Earlei. 
Rays yellow, oblong or somewhat cuneate. 4. H. -floribunda. 
Plant tall, 3 dm. high or more, biennial or short-lived perennial, with one or 
few stems from a tap-root. 
Stem simple below; leaves pinnate or simple ; disk over x cm. wide. 
5. H. helenioides. 
Stem diffusely branched; leaves once to thrice ternate; disk 5-8 mm. wide. 
6. H. multiflora. 
1. Hymenoxys macrantha (A. Nels.) Rydb. ( Picradenia macrantha A. 
Nels.; H. Richardsonii macrantha Cockerell) In dry soil from Wyo. to Utah 
and Colo.—Como; South Park. 
2. Hymenoxys pumila (Greene) Rydb. ( Picradenia pumila Greene; H. 
Richardsonii pumila Cockerell) Very dry hills from Ass. to Colo, and Utah. 
—North Park. 
3. Hymenoxys Earlei Cockerell. In the pinon belt of Colo.—Mancos. 
4. Hymenoxys floribunda (A. Gray) Cockerell. ( Actinella Richardsonii 
floribunda A. Gray; Picradenia floribunda Greene) In dry or gravelly soil 
from Colo, to N. M. and Ariz.—Alt. 4000-10,000 ft.—Como; Buena Vista; 
Marshall Pass; Placer; Westcliffe; Twin Lakes; Mancos; Gunnison; Sangre 
de Cristo Creek; Turkey Creek and tributaries; Mt. Harvard; dry plains 
south of Antonito; Dillon Canon; Nepesta; Colorado Springs. 
