C. NAUSEOSUS. 211 



The difficulties encountered in an attempt to assign specific rank to the more striking 

 variations are indicated somewhat in table 23, where the principal characters are tabu- 

 lated. The principal characteristics of the 20 subspecies are given in the key on page 210 

 and the subspecies themselves are given a diagrammatic presentation on page 223. 



12a. Chrysothamnus naxjseosus gnaphalodes (Greene). — Shrub 5 to 15 or rarely 25 

 dm. high, usually globoid in outline, with very many short twiggy branches; twigs erect 

 or spreading, not densely leafy, obscurely striate, yellowish green or gray with a closely 

 packed tomentum; herbage usually very fragrant; leaves 2 to 4 cm. long, 1 mm. or less 

 wide, those of the end twigs only 1 to 3 cm. long and often recurved, 1-nerved, gray- 

 tomentose; inflorescence a rounded cyme terminating each of the twigs; involucre about 

 7 (6 to 8) mm. high; bracts rather obtuse, keeled, in 5 distinct vertical rows, tomentose, 

 not ciliate; corolla 7 to 8 mm. long; tube sparsely pubescent with short crisp or rigid 

 hairs; lobes ovate, acute, 0.5 to 1 mm. long, erect or even connivent around the stamen- 

 tube; style-appendage shorter than the stigmatic part; achenes densely pubescent. 

 (C. speciosus var. gnaphalodes, Greene, Erythea 3:110, 1895.) Abundant on gravelly 

 and sandy non-alkaline slopes and benches of western Nevada, eastern California (and 

 northern Arizona?). Tj^pe locality, Pyramid Lake, Nevada. Collections: Pyramid 

 Lake, Nevada, 1883, Curran (Univ. Calif. Herb. 87247, probably the type); Fallon, 

 Nevada, Heller 10680 (DS, Gr, NY); California: Benton, Mono County, Hall 10655 

 (UC); White Mountains, Inyo County, Hall 10631 (UC); west of Lancaster, Los Ange- 

 les County, Hall 10585 (SF, UC); Banning, westerly edge of Colorado Desert, September 

 27, 1894, Tourney (UC); mesas near Colton, Parish 2057 (DS). 



126. Chrysothamnus natjseosus hololeucus (Gray).^ — Shrub 6 to 18 dm. high and 

 fully as broad, closely branched and usually of rounded outline; twigs erect, leafy to the 

 top, not striate, white with a permanent dense tomentum ; herbage exceedingly fragrant ; 

 leaves linear, 1 to 3 cm. long, about 1 but sometimes nearly 2 mm. wide, 1-nerved, per- 

 manently white-tomentose ; inflorescence a rounded often compact cyme; involucre 6 to 

 7 mm. high; bracts very obtuse, plainly keeled and in 5 distinct vertical ranks, woolly 

 but not ciliate; corolla 6.5 to 8 mm. long; tube minutely puberulent and also more or less 

 cobwebby with loose hairs or these occasionally wanting; lobes ovate, acute, strictly 

 erect, 0.5 to 1 mm. long; style-appendage shorter than the stigmatic part; achenes densely 

 pubescent. (Bigelotda graveolens var. hololeuca Gray, Proc. Am. Acad. 8:645, 1873.) 

 Gravelly or sandy well-drained slopes of western Nevada and eastern California extending 

 southward as far as Antelope Valley. Type locality, Owens Valley, California. Col- 

 lections: Sutcliffe, Pyramid Lake, Nevada, Hall 10884 (UC); near Lida, Esmeralda 

 County, Nevada, Hall 10818 (UC); Benton, Mono County, California, Hall 10643 (UC); 

 Independence, Inyo County, California, Hall 10615 (SF, UC); type collection, Horn (Gr). 



12c. Chrysothamnus nauseosus speciosus (Nuttall). — Shrub commonly 6 to 20 dm. 

 high (or only 4 dm. in the far west), broad and rounded; twigs mostly erect, with long 

 leaves to the summit, striate but the striae often obscure, greenish white, the tomentum 

 comparatively smooth; herbage nearly inodorous; leaves linear, 2 to 6 cm. long, typically 

 about 1 mm. wide but varying to 3 mm. (see minor variation 58); 1-nerved, usually erect 

 or ascending, becoming dense toward the inflorescences and there scarcely reduced in size, 

 gray, tomentose or the tomentum partly deciduous and the foliage then greenish; inflor- 

 escence a round-topped or somewhat elongated cyme, commonly loose; involucre 8 to 

 10 mm. high ; bracts acute, strongly keeled, in obvious vertical rows, either tomentulose 

 on the back or all but the very short outermost ones glabrous (as in the tjqDe), not ciliate; 

 corolla 8 to 10 or rarely 11 mm. long; tube sparsely puberulent or glabrous; lobes 0.8 to 2 

 mm. long; style-appendage longer than the stigmatic part; achenes densely pubescent. 



