37(i CARDUACEAE. 



4. Thelespertna subnudum A. Gray. On dry plains of Colo., Utah, N. M. 

 and Ariz. — Alt. 4500-7000 ft. — Branlly Canon, Las Animas Co.; Grand Junc- 

 tion; Cedar Hills; Walsenburg; dry hills about Antonito. 



5. Thelesperma gracile A. Gray. On dry plains from Neb. and Colo, to 

 Tex. and Ariz. — Alt. 4000-10,000 ft. — Colorado Springs; near Boulder; Mani- 

 tou; New Windsor; Denver; Ft. Collins; between Sunshine and Ward;. Fos- 

 sil Creek; Wray; Raton Range; Poudre River. 



56. MADIA Molina. Tar-weed. 



I. Madia glomerata Hook. In open dry places in the mountains from 

 Sask. and B. C. to Colo.— Alt. 6500-9000 ft.— Valley near Empire; Rabbits-Ear 

 Pass; Cerro Summit; Pagosa Springs; Gunnison Co.; Hubbard Creek; Dale 

 Creek; Steamboat Springs; between Pallas and Sydney; Hotchkiss; Hayden. 



Tribe 5. HELENIAE. 



57. PSILOSTROPHE DC. 



Scales of the pappus one-third as long as the disk-corollas, mostly obtuse ; leaves 

 broadly spatulate ; rays 8-12 mm. long, indistinctly nerved. i. P. Bakeri. 



Scales of the pappus one-half as long as the disk-corollas, acute or acuminate ; 

 rays 5-8 mm. long, distinctly veined. 2. P. tagetina. 



1. Psilostrophe Bakeri Greene. (Riddellia tagetina pumila Jones ; P. piimila 

 A. Nels.) On dry plains and hills in Colo, and Utah.— Alt. 5500 ft.— Uncom- 

 pahgre Mountains, near Los Pinos ; Rifle, Garfield Co. ; Grand Junction ; 

 Delta Co.; Montrose; Hotchkiss; Palisades. 



2. Psilostrophe tagetina (Nutt.) Greene. {Riddellia tagetina Nutt.) On 

 dry plains from Colo, to Tex. and Ariz. — Sources of the Platte. 



58. PERICOME A. Gray. 



I. Pericome caudata A. Gray. In canons and river valleys from Colo, to 

 Tex. and N. M. ; also in Mex.— Alt. 5000-8000 ft.— North Cheyenne Caiion; 

 Manitou; Engelmann Caiion; Colorado Springs; Marshall Pass; Ute Pass. 



59. HYMENOPAPPUS L'Her. 



Throat of the corolla 1-1.5 mm. long, not over twice as long as the lobes. 

 Pappus not hidden by the hairs of the achenes. 



Stem permanently densely white-tomentose ; achenes silky. 



1. H. arenosus. 

 Stem sparingly grayish-tomentose, glabrate in age ; achenes loosely villous. 



2. H. cinereus. 

 Pappus hidden by the hairs of the achenes, or sometimes none. 



3. H. filifolius. 

 Throat of the corolla 3-4 times as long as the lobes. 



Pappus shorter than the corolla-tube ; throat of corolla 3-4 mm. long ; plant tall. 



4. H. macroglottis. 

 Pappus equalling the corolla-tube: throat about 1.5 mm. long; plant dwarf. 



5. H. parvulus. 



I. Hymenopappus arenosus Heller. On dry hills and plains from Colo, and 

 Utah to N. M. — .A.lt. 5000-7000 ft. — Arboles; Dolores; hills above Trinidad; 

 Grand Junction ; Mancos ; Florence. 



