OregonFlora: Arnica lanceolata vs. Arnica

	Arnica lanceolata	Arnica
	clasping arnica, streambank arnica	arnica
Habit		Herbs perennial; usually rhizomatous, sometimes strongly so.
Stems		erect; simple or branched, sometimes with basal offshoots or accessory; non-flowering basal rosettes, glabrous or pubescent, often glandular.
Leaves		basal and cauline; opposite, triangular to ovate, lanceolate, or elliptic; margins entire to dentate or serrate; tips obtuse or acute; surfaces glabrous to pubescent and/or glandular, sessile or petiolate.
Inflorescences		solitary terminal heads, sometimes few to numerous additional heads in axils of upper bracts and leaves, or on bracteate axillary branches.
Involucres		campanulate, hemispheric, or turbinate.
Receptacles		convex; paleae 0.
Ray florets		0 or pistillate, yellow to orange.
Disc florets		bisexual; corollas tubular, linear below, widened and cylindric distally, yellow or rarely cream, moderately or densely pilose and stipitate-glandular, 5-lobed; lobes triangular, recurved; style branches slightly exserted from stamen tubes.
Phyllaries		few to numerous in 1–2 equal series; ovate to lanceolate or narrowly lance-elliptic; surfaces usually pubescent, often stipitate-glandular, sometimes with a tuft of adaxial hairs at tips.
Fruits		cylindric, conic, or fusiform, gray or blackish, 5–10-veined, glabrous to densely strigose or hirsute, glandular-pubescent or not, pappi of 10–50 barbellate, subplumose, or plumose bristles.
Heads		radiate or discoid, usually erect.

	Arnica lanceolata	Arnica
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion		Circumboreal. 29 species; 17 treated in Flora. Arnica species exhibit considerable morphologic variability as a result of frequent polyploidy and apomixis, often making identification difficult.
Source		Flora of Oregon, volume 2, page 182 Kenton Chambers
Sibling taxa	A. cernua, A. chamissonis, A. cordifolia, A. discoidea, A. diversifolia, A. fulgens, A. gracilis, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
Subordinate taxa	A. lanceolata ssp. prima	A. cernua, A. chamissonis, A. cordifolia, A. discoidea, A. diversifolia, A. fulgens, A. gracilis, A. lanceolata, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Arnica lanceolata

Arnica

clasping arnica, streambank arnica

arnica

Habit

Herbs perennial; usually rhizomatous, sometimes strongly so.

Stems

erect; simple or branched, sometimes with basal offshoots or accessory; non-flowering basal rosettes, glabrous or pubescent, often glandular.

Leaves

basal and cauline; opposite, triangular to ovate, lanceolate, or elliptic;

margins entire to dentate or serrate;

tips obtuse or acute;

surfaces glabrous to pubescent and/or glandular, sessile or petiolate.

Inflorescences

solitary terminal heads, sometimes few to numerous additional heads in axils of upper bracts and leaves, or on bracteate axillary branches.

Involucres

campanulate, hemispheric, or turbinate.

Receptacles

convex;

paleae 0.

Ray florets

0 or pistillate, yellow to orange.

Disc florets

bisexual;

corollas tubular, linear below, widened and cylindric distally, yellow or rarely cream, moderately or densely pilose and stipitate-glandular, 5-lobed;

lobes triangular, recurved;

style branches slightly exserted from stamen tubes.

Phyllaries

few to numerous in 1–2 equal series; ovate to lanceolate or narrowly lance-elliptic;

surfaces usually pubescent, often stipitate-glandular, sometimes with a tuft of adaxial hairs at tips.

Fruits

cylindric, conic, or fusiform, gray or blackish, 5–10-veined, glabrous to densely strigose or hirsute, glandular-pubescent or not, pappi of 10–50 barbellate, subplumose, or plumose bristles.

Heads

radiate or discoid, usually erect.