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heart-leaf arnica, heart-leaf leopardbane

Lake Louise arnica, snow arnica

Habit Plants 10–40(–70) cm. Plants 5–20 cm.
Stems

usually simple, sometimes branched.

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).

1–3 pairs, mostly cauline (shorter plants often with leaves crowed mostly toward bases); petiolate;

blades elliptic, oblong, or ovate-lanceolate, 1.5–7.5 × 0.5–2 cm, margins usually entire, rarely denticulate or slightly undulate, apices usually obtuse, sometimes acute or acuminate, faces glabrous or hispidulous-puberulent, ± densely stipitate-glandular.

Involucres

broadly campanulate.

campanulate-turbinate.

Ray florets

6–13;

corollas yellow.

7–10;

corollas yellow.

Disc florets

corollas yellow;

anthers yellow.

corollas yellow;

anthers yellow.

Phyllaries

10–20, narrowly ovate to lanceolate.

10–20, narrowly lanceolate (stipitate-glandular).

Heads

1, or 3–5(–10).

usually 1, sometimes 2–3 (nodding at flowering).

Cypselae

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

pappi white, bristles barbellate.

brown, 3–5 mm, abaxially glabrous, adaxially sparsely hirsute or glabrous throughout, usually stipitate-glandular toward apices, sometimes densely stipitate-glandular throughout;

pappi white, bristles barbellate.

2n

= 38, 57, 76, 95, 114.

= 76, 95.

Arnica cordifolia

Arnica louiseana

Phenology Flowering May–Jul. Flowering Jul–Aug.
Habitat Conifer forests to subalpine meadows Exposed tundra slopes and calcareous rock slides
Elevation 500–3000 m (1600–9800 ft) 1800–2100 m (5900–6900 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
AB; BC
[BONAP county map]
Source FNA vol. 21, p. 374. FNA vol. 21, p. 371.
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. longifolia, 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
Name authority Hooker: Fl. Bor.-Amer. 1: 331. (1834) Farr: Ottawa Naturalist 20: 109. (1906)
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