COMPOSITAE. I02I 



lucre short-oblong, canescent or tomentose, its bracts oblong, obtuse. Kans. (ac« 

 cording to Smyth), and Colo, to Ariz. Aug.-Oct. 



21. Artemisia tridentata Nutt. Common Sage-bush. Sage-brush. 

 Sage-wood. Mountain Sage. (I. F. f. 4017.) Shrubby, silvery-canescent; 

 stem much branched, 3-35 dm. high. Leaves narrowly cuneate, 1-4 cm. long, 

 2-6 mm. wide, sessile, 3-7-toothed at the truncate apex; heads very numerous, 

 5-8-flowered. about 3 mm. broad, sessile, or very nearly so, in large dense panicles; 

 involucre oblong, tomentose, its inner bracts oblong, the outer short, ovate, all ob- 

 tuse or obtusish. On dry plains and in rocky soil, western Neb. to Colo., Utah and 

 Cal., north to Mont, and Br. Col. July-Sept. 



22. Artemisia cana Pursh. Hoary Sage-bush. (I. F. f. 4018.) Shrubby, 

 densely white-canescent; stem much branched, 3-7 dm. high. Leaves linear, 

 linear-oblong or narrowly lanceolate, sessile, acute at both ends, 3-5 cm. long, 

 3-6 mm. wide, usually quite entire, rarely with 2 or 3 acute teeth or lobes; heads 

 numerous, about 3 mm. broad, glomerate or sometimes solitary in the axils of the 

 leaves, or crowded into a naked thyrsus at the summit, 5-9 flowered; involucre 

 oblong, canescent, its inner bracts oblong or lanceolate, obtuse, usually with 1-3 

 shorter outer ones. Plains, Neb. and Colo, to N. Dak. and the N. W. Terr. July- 

 Sept. 



89. TUSSILAGO L. 



An acaulescent herb, more or less white-tomentose, with slender perennial root- 

 stocks, broad basal cordate, dentate or lobed, long-petioled leaves, and large soli- 

 tary, monoecious heads of both tubular and radiate yellow flowers at the summit 

 of a scaly scape, appearing before the leaves of the season. Involucre campanu- 

 late to cylindric, its principal bracts in a single series, equal, with or without a 

 few shorter outer ones. Receptacle flat, naked. Ray-flowers in several series, 

 pistillate, fertile. Disk-flowers perfect, sterile, the corolla 5 -cleft, the style undi. 

 vided and obtuse. Achenes of the ray-flowers linear, 5-10-ribbed. Pappus 

 copious, of numerous slender roughish bristles, that of the sterile flowers shorter 

 than that of the fertile. [Latin, tussis, cough, for which the plant was a reputed 

 remedy.] A monotypic genus. 



1. Tussilago FarfaraL. Coltsfoot. Coughwort. (I. F. f. 4019.) Scape 

 slender, 7-45 cm. high, bearing a solitary large head at the summit. Leaves 

 nearly orbicular, or broadly ovate-reniform, angulately lobed and dentate, 7-16 

 cm. broad, green and glabrous above, persistently white-tomentose beneath; head 

 about 25 mm. broad; involucre campanulate ; rays bright yellow, numerous, linear, 

 pistillate, fertile. In moist soil, along roadsides, etc., N. S. and N. B. to Mass., 

 N. Y. and Minn. Nat. from Europe. April-June. 



90. PETASITES Gaertn. 



Herbs with perennial thick horizontal rootstocks, broad basal petioled leaves, 

 and scaly scapes bearing racemose or corymbose heads of tubular or both tubular 

 and radiate, white or purplish, often dioecious or subdioecious flowers. Involucre 

 campanulate to cylindric, its bracts in 1 series, equal. Receptacle flat, or nearly 

 so, not chaffy. Corolla of pistillate flowers very slender, 2-5 -toothed, truncate or 

 sometimes with a ray, marginal, or composing most of the head; perfect but sterile 

 flowers with a tubular 5-cleft corolla, the style undivided. Anthers entire or 

 minutely sagittate at the base. Fertile achenes linear, the pappus of numerous 

 capillary rough or barbellate bristles. [Greek, a broad-rimmed hat, referring to 

 the broad leaves of these plants.] About 12 species, natives of the north temperate 

 and subarctic zones. 



Flowers whitish, the pistillate radiate ; natives ; northern. 



Leaves orbicular, 7-11-cleft nearly to the base. I. P. palmata. 



Leaves hastate- reniform, sinuate-lobed or toothed. 2. P./rigida. 



Leaves deltoid-ovate, repand-denticulate. 3. P. sagittata. 



Flowers all rayless, purple; introduced. 4. P. Petasites. 



i. Petasites palmata (Ait.) A. Gray. Palmate-leaf Sweet Coltsfoot. 

 (I. F. f. 4020.) Scape very scaly, stout, 1.5-6 dm. high. Leaves 7-30 cm. broad, 

 green and glabrous above, densely white-tomentose beneath, at least when young, 



