414 COMPOSITE. Senecio. 



14. S. aronicoides, DC. Loosely and somewhat hirsutely woolly when young, 

 glabrous when old : stem stout, a foot to a yard high, bearing numerous small heads 

 in dense compound cymose clusters : leaves oblong, varying to ovate or lanceolate 

 (3 to 5 inches long), irregularly and often coarsely toothed, or the lower cauline 

 sometimes laciniate-pinnatifid, the uppermost reduced to bracts : scales of the invo- 

 lucre lanceolate, acuminate, not black-tipped : rays none, or occasionally one or two 

 short ones : disk-flowers 10 to 20. — S. exaltatus var. uniflosculosus, Gray in Pacif. 

 E. Eep. iv. 111. 



Low grounds, common about the Bay of San Francisco, the Geysers, &c. A dwarf and nearly 

 entire-leaved variety, around Lassen's Peak, Lemmon. Involucre 3 lines long. 



15. S. hydrophilus, Nutt. Very glabrous apparently from the first, pale or 

 even glaucous : stem stout, 2 to 4 feet high, many-leaved and bearing numerous 

 paniculate-corymbose small heads : leaves thickish, entire or occasionally denticulate 

 or repand, mostly lanceolate, with broad and strong midrib ; the lower 5 to 9 inches 

 long and tapering into a stout petiole ; the upper successively shorter and sessile : 

 scales of the narrow involucre oblong-linear, rather obtuse, mostly brownish-tipped : 

 rays 2 to 6 and linear, or sometimes wanting : disk-flowers 8 to 20. — Torr. & Gray, 

 Fl. ii. 440. 



Wet grounds, Lake Co. and Shasta Co. {Brewer) ; salt marsh at Yallejo (Greene) ; in the Sierra 

 at Mono Pass (Bolcinder) ; near Carson (Anderson) ; and thence to the Rocky Mountains. A 

 peculiar species. Involucre S lines long, in specimens from Vallejo 4 lines long and rayless. 



++ -s-i- ++ Tall, 2 to 5 feet high, equably leafy to the top, glabrous throughout or nearly 

 so, not woolly when young : involucre cylindraceous, subtended by a few loose and 

 nearly setaceous bracts : akenes glabrous. 



1 6. S. Andinus, iSTutt. Stems extremely leafy, often branching : leaves lan- 

 ceolate or linear-lanceolate (or the lower oblong), tapering to both ends, either 

 sharply and closely denticulate or entire ; the cauline nearly sessile : heads small, 

 very numerous, corymbose-paniculate. : rays 6 to 8. 



Near Carson City, Nevada (Anderson), and therefore probably within the limits of the State : 

 not rare northward and eastward to the Rocky Mountains, along streams. Heads variable in 

 size and in number of the flowers, from 4 to 6 lines high. 



1 7. S. triangularis, Hook. Stems mostly simple : leaves all but the upper- 

 most petioled and deltoid or triangular-lanceolate, or even hastate, acuminate, 

 thickly dentate (either coarsely or sometimes finely) with sharp salient teeth : heads 

 rather numerous, wnynibose : rays 6 to 12. — Hook. Fl. ii. 332, t. 115. 



Low or wooded moist grounds of the Sierra Nevada ; Mariposa Grove, &c. (Brewer, Bolander), 

 Donner Lake (Torrey), Sierra Valley (Lemmon) ; through Nevada to the Rocky Mountains, and 

 north to British Columbia. Heads varying from 4 to 7 lines high. 



102. ARNICA, Linn. 

 Head many-flowered, with pistillate rays, or sometimes homogamous by the 

 absence of the rays ; the flowers all fertile. Involucre usually broadly campanulate, 

 naked at base ; the scales thin-herbaceous, lanceolate or linear, equal, in one or two 

 series. Receptacle flat, naked. Hays elongated : disk-corollas with distinct and 

 usually elongated tube and funnelform or cylindraceous 5-lobed limb. Style-append- 

 ages obtuse, pubescent. Akenes linear, 5-angled or 5-10-ribbed, somewhat hirsute 

 or nearly glabrous. Pappus a single series of rather rigid strongly scabrous or 

 barbellate capillary bristles.- — Perennial herbs; with mostly simple stems from 

 creeping rootstocks, bearing solitary or few usually long-peduncled and rather large 

 heads of yellow flowers ; the leaves opposite (!) or in one or two Californian species 

 occasionally alternate, simple, entire or merely toothed. 



