CATALOGUE. 193 



363. Scurfy-pubescent and mealy ; leaves broadly triangular, the lower ones 

 somewhat reniform, irregularly dentate, 3-6" long and broad ; heads axillary 

 or subcorymbose, at length nodding ; involucral scales in two rows, 5 outer 

 subfoliaceous lanceolate and persistent, and 12-15 inner scarious 2-4-nerved 

 deciduous ones ; corolla very slender, the apex pubescent with a few long 

 crisped webby hairs ; achenia very villous, the hairs rather rigid and often 

 slightly bifid at the extremity. — A low branching whitish herb, with the look 

 of Obione argentea. New Mexico to California ; Humboldt Plains, Nevada, 

 (Torrey.) Carson Desert, and near Hot Springs in the Hot Spring Mount- 

 ains, Nevada; 4—4,500 feet elevation; July, August. (680.) 



Tetradymia^ canescens, DC. Densely white-tomentose ; leaves hnear, 

 6-12" long and about 1" wide, rigid, mucronate, but not spinescent, axillary 

 fascicles of smaller leaves none ; heads racemose-corymbed ; involucre 5-6" 

 long, of 4 oblong obtuse carinate scales ; florets 4 ; achenia sparingly villous 

 with soft short hairs, soon becoming nearly smooth. — Shrubby, forming a 

 densely branched bush 1-3° high, the main stem often 2' thick at the base. 

 The same habit is common to all the genus. — British Columbia, Oregon and 

 California ; Mt. Davidson, (Bloomer.) Virginia, Truckee and East Humboldt 

 Mountains; 6-9,000 feet elevation; July, August. (681.) 



Var. iNEEMis, Grray. {T. inermis, Nutt.) Leaves shorter, acute, but 

 scarcely mucronate ; heads smaller ; involucral scales 2-4" long. — Southern 

 Oregon to Wyoming, Colorado and New Mexico ; Western Nevada, (Ander- 

 son, Bloomer.) Toyabe Range, Huntington and Ruby Valleys, Nevada, and 

 Silver Creek Canon, near Parley's Park, Utah, on dry hillsides; 6-7,000 feet 

 elevation. (682.) 



Tetradtmia glabrata, T. & G. Pac. R. R. Rep. 2. 122, t. 5. Branches 

 white-tomentose ; leaves soon glabrate, somewhat fleshy ; primary ones erect, 



the connective with an ovate acute point, and tlie cells slightly produced at the base. Style included, 

 the branches short, stigmatic to the summit, and crowned with a very short truncate villous appendage. 

 Achenia oblong or top-shaped, densely villous. Pappus of numerous unequal slightly scabrous rather 

 rigid bristles, the longest half the length of the corolla. — Low heavy-scented annuals or biennials, viscid 

 or mealy-pubescent, with alternate petioled leaves and yellow flowers. Natives of New Mexico, Califor-- 

 nia, &c. 



' TETRADTMIA, DC. Heads 4-flowered, (in one species 5-9-flowered;) the flowers all tubular, 

 perfect and fertile ; the corollas funnelform with a long slender tube, deeply 5-lobed, the linear lobes 

 slightly recurved. Involucre of 4 (rarely 5-6) subeqnal concave-carinate rigid oblong scales. Receptacle 

 very small, naked. Anthers linear, exserted. Branches of the style linear, with very short ovate obtuse 

 pubescent appendages. Achenia oblong-linear, villous or glabrate. Pappus copious, of very fine unequal 

 capillary denticulate filaments as long as the tube of the corolla. — Low much-branched shrubs, of Oregon, 

 California, New Mexico, &c. ; often densely white-tomentose, with small rigid linear or subulate sessile 

 alternate leaves, the primary ones often becoming spiny. Heads rather large, solitary on short branch-- 

 lets, or forming small terminal and snbterminal clusters ; flowers yellow. 

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