11.
Arnica chamissonis
Lessing, Linnaea. 6: 238. 1831.
Chamisso arnica, leafy arnica, arnica de Chamisso
Arnica bernardina
Greene;
A. chamissonis
var.
bernardina
(Greene) Jepson ex Maguire;
A. chamissonis
subsp.
foliosa
(Nuttall) Maguire;
A. chamissonis
var.
foliosa
(Nuttall) Maguire;
A. chamissonis
subsp.
incana
(A. Gray) Maguire;
A. chamissonis
var.
incana
(A. Gray) Hultén;
A. chamissonis
var.
interior
Maguire;
A. chamissonis
var.
jepsoniana
Maguire;
A. foliosa
Nuttall
Plants
20—80(—150) cm.
Stems
usually branched from mid heights or distally.
Leaves
4—10 pairs, mostly cauline (evenly distributed; basal leaves often withered by flowering, 1—2 pairs, subsessile to short-petiolate); sessile (proximalmost with membranous connate-sheathing bases); blades lance-elliptic, broadly oblanceolate, or oblong, 5—20 × 2—6(—8) cm, margins entire or remotely denticulate to prominently dentate, apices acute, faces nearly glabrous or puberulent to sparsely or densely white-tomentose-pilose.
Heads
(1—)3—10(—16).
Involucres
campanulate (rarely hemispheric).
Phyllaries
8—23, nearly linear to narrowly lanceolate (apices each with conspicuous tuft of white hairs).
Ray florets
8—20; corollas yellow.
Disc florets:
corollas yellow; anthers yellow.
Cypselae
gray to brown, 3—8 mm, subglabrous to sparsely hirsutulous, stipitate-glandular;
pappi
stramineous, bristles barbellate to subplumose.
2
n
= 38, 57, 76.
Flowering Apr—Sep. Moist meadows and conifer forests, stream banks, late snow-melt areas, often montane to subalpine; 0—3500 m; Alta., B.C., Man., N.W.T., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.
