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heart-leaf arnica, heart-leaf leopardbane

long-leaf arnica, seep-spring arnica, spear-leaf arnica, spear-leaf leopardbane

Habit Plants 10–40(–70) cm. Plants 30–60(–110) cm.
Stems

usually simple, sometimes branched.

(often relatively numerous, clustered in clonal patches) simple.

Leaves

2–4(–6) pairs, mostly cauline (basal often persistent on sterile rosettes); petiolate;

blades cordate or subcordate to ovate, 3–10 × 2–10 cm, margins dentate to coarsely dentate, apices acute to rounded, faces puberulent to sparsely villous, sometimes stipitate-glandular (especially adaxial).

5–7 pairs, mostly cauline (basal leaves usually withered by flowering);

sessile or subsessile (proximalmost with connate-sheathing bases);

blades lanceolate to lance-elliptic, 5–12(–15) × 1.5–3.5 cm, margins usually entire, rarely denticulate, apices acute to acuminate, faces scabrid-puberulent, sometimes glandular (distal leaves not much reduced).

Involucres

broadly campanulate.

turbinate-campanulate.

Ray florets

6–13;

corollas yellow.

6–15;

corollas yellow.

Disc florets

corollas yellow;

anthers yellow.

6–11;

corollas yellow;

anthers yellow.

Phyllaries

10–20, narrowly ovate to lanceolate.

11–15(–20), narrow to broadly lanceolate.

Heads

1, or 3–5(–10).

3–20(–35).

Cypselae

dark gray, 5–10 mm, sparsely to densely hirsute (hairs duplex), sometimes stipitate-glandular as well;

pappi white, bristles barbellate.

brown to black, 3–7 mm, glabrous or sparsely hirsutulous, stipitate-glandular;

pappi stramineous to tawny, bristles barbellate to subplumose.

2n

= 38, 57, 76, 95, 114.

= 57, 76.

Arnica cordifolia

Arnica longifolia

Phenology Flowering May–Jul. Flowering Jun–Oct.
Habitat Conifer forests to subalpine meadows Montane coniferous forests to alpine, usually moist areas, stream banks or late snow-melt areas
Elevation 500–3000 m (1600–9800 ft) 1300–3700 m (4300–12100 ft)
Distribution
from FNA
AZ; CA; CO; ID; MI; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; NT; ON; SK; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 21, p. 374. FNA vol. 21, p. 374.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Arnica Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Arnica
Sibling taxa
A. acaulis, A. angustifolia, A. cernua, A. chamissonis, A. dealbata, A. discoidea, A. fulgens, A. gracilis, A. griscomii, A. lanceolata, A. latifolia, A. lessingii, A. lonchophylla, A. longifolia, A. louiseana, A. mollis, A. nevadensis, A. ovata, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. unalaschcensis, A. venosa, A. viscosa
A. acaulis, A. angustifolia, A. cernua, A. chamissonis, A. cordifolia, A. dealbata, A. discoidea, A. fulgens, A. gracilis, A. griscomii, A. lanceolata, A. latifolia, A. lessingii, A. lonchophylla, A. louiseana, A. mollis, A. nevadensis, A. ovata, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. unalaschcensis, A. venosa, A. viscosa
Synonyms A. cordifolia var. pumila, A. paniculata, A. whitneyi A. longifolia subsp. myriadenia, A. myriadenia
Name authority Hooker: Fl. Bor.-Amer. 1: 331. (1834) D. C. Eaton: in S. Watson, Botany (Fortieth Parallel), 186. (1871)
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