418 COMPOSITAE 
108. ARNICA L. Sp. Pl. 884. 1753. 
Heads radiate or discoid, the rays when present pistillate and fertile, yellow or orange, 
relatively few and broad. Involucral bracts herba aceous, more or less evidently biseriate but 
ubeq nd connivent. Receptacle convex or nearly flat, naked. Disk- ers f 
or 
perennial herbs from a rhizome or caudex. Leaves sim nple, opposite, or the reduced upper-. 
most.ones occasionally alternate. Heads rather large, turbinate to per eit ae to 
rather numerous. [Name of uncertain duccaten perhaps a corruption of Pta 
A genus of about 30 species, of circumboreal distribution but most highly developed in western North 
sengy  o ask species, Arnica ~~ ontana 
pecies—A. alpina, A. chamissonis, and A girder Aegati have been reported to s and 
the hess ont i of these, at rate may well prove to be argely or wholly apomictic. Some ane "the roan: in 
specific delimitation suggest the existence of a polyploid- Pekan Me complex, but this remains to be demonstrated. 
Heads characteristically radiate Seero ioc rayless forms of some of these species occur, chiefly in company 
with the normal radiate plants). 
Cauline —— relatively numerous and well developed, mostly 5-12 p 
nvolucral bracts obtuse or merely acutish, bearing | a tuft of dain hairs at or just within the tip; 
apn es elongate and oe naked, t 1. A. chamissonis. 
Involucral ig Vo more or tes shar pooh the tip not markedly more hairy than the y. 
ntire or ne s densely —— d (often in very large clones), the rhizome com- 
nly pi Aaa Tats a branching cau 2. A —— 
Leaves more or less toothed; tufted, the rhizomes mostly more elongat 
J. As Saiieeicondls. 
Cauline leaves few, mostly 2-4(5) pairs, not including those, if ids of the basal cluste 
Rays short, mostly 7-15 mm. long; lower petioles and lower part of the stem n densely and ae ipa 
pul ubescent with long, loosely spreading hairs; veer heads nodding; n Ca pei 
Rays a mostly 1.5-3 cm. long or occasionally a little shorter in some ousits ee he not have 
conspicuous long hairs; heads erect; widespread. 
Pues Aa 3 el gl umose, more or less tawny; rhizomes freely rooting, often shortened into 
Heads broad, mostly subhemispheric; cauline leaves variable in shape; ge ee Riccio 
the best a. . A, mollis. 
Heads narrow turbinate; cauline leaves relatively broad, mosty adc or oid 
to br sati er tanag a broadly lance- elliptic, the middle ones ign ta we ie the Sheree a 
olia, 
Pappus merely barbellate, or becoming weakly subplumose in some species =< Taste, nearly 
naked rhizomes, generally white or nearly so 
Leaf-blades relatively narrow, mostly (2. 5)3- 10 times as long as wide; basal leaves often 
TF rcdbeni —— but not always so; rhizomes short and freely rooting except sometimes in 
Heads lative large, hemispheric or: nearly so, with mostly 10-23 (about 13 or about 
21 hag Mt lower aogag leaves generally petiolate; foothills and moderate wend 
tions in the mountai 
Old leaf sme with ve nse tufts of long brown wool in the axils; _ disk-corollas with some 
eading glandless hairs as well as commonly 
7. A. fulgen 
Old wee age without axillary tufts or the hairs few and white; disk- eels stipi- 
wapecane generally not otherwise hairy. 8. sororia 
Heads ee ,» with mostly 7-10 (about 8) rays; inter cauline 
leaves ede to be sessile; - d 9; Aa page nee 
Leaf- — Bain! std broad, the lar ones mostly “8 2.5(3) times as long wide; basal 
S sometimes persistent rug pat Seneety tufted; PDE Mee in “forms of A. lati- 
anton elongate and subnaked, sometimes subapically branched and more scaly. 
Achenes generally glabrous below or glabrous throughout; basal leaves (those on separate 
short shoots) seldom cordate when present, the cauline ones even less Pireate uently 
so; leaves generally more or less toothed; sapeleers wit tn few 24 no long hairs. 
Pappus BS i Lay sere Feng 1 to several; plants w gs oce ane on 
not so Sidhew A pyre rine from June to 
Aue 10. A. latifolia. 
Pappus eure subplumose; ages strictly solitary; ~— res Bi” ~, Cag tnd 
in and near the Klamath region, flowering mostly in April a y (June). 
1; A pl mi : 
Achenes mostly short-hairy (or glandular) a, or = to the base; leaves and in- 
volucre various but mos’ ag he not prese g the foregoing combina tion of characters. 
ppteeeal bracts obtuse or ey eee ae had cha a ge tuft of hairs within; 
s ( 3)5-7 : laces OG thin y tetutcas. ovate iy orate die ieee not cordate; 
sa ge of the Sierra Nevada and Klamat 
ie. a zasteit 
pe bracts m or less sharply acute, mostly without any very promin 
~ tuft pg taire: heads commonly 1-3, or sometimes more in Senta oi 
ares leaves either glandular (rather than tomentulose) or cordate; 
iano speci: 
Involucre with geen or no long hairs; leaves entire or nearly so, the low 
br — rolendel to oe at the base; lateral setae of the pa) pus 
stles more prominent in either A. Jat atifolia or A. cordifolia; 
ponicinek in hy Sierra Ne mak: extending budmdan te less commonly, to 
| sagan . A. nevadensis. 
Involucre to usually copiously periited. p with Sk white hairs, es 
cally ¢ onc the base; — toothed t etimes entire, the basal and 
enerally also the lower cauline ones tiuncauasty more or less strongly cor- 
