Parry's Arnica

Plants 15–50(–60) cm. Stems simple or branched among heads. Leaves (2–)3–4 pairs, basal and cauline (basal usually withered by flowering, petiolate or subsessile, blades ovate or nearly round to oblong-ovate, much smaller than cauline; sterile rosettes often present, proximal cauline often crowded toward stems bases); petiolate; blades broadly to narrowly lanceolate, oblong-ovate, ovate-lanceolate, or round, 4–22 × 1–6 cm, (bases obtuse or cuneate to truncate) margins usually entire, sometimes sparsely denticulate, faces scantily to moderately pilose (hairs white), adaxial sparsely stipitate-glandular (distal cauline leaves sessile, extremely reduced, nearly linear to narrowly elliptic-lanceolate). Heads (1–)3–9(–14; often nodding in bud). Involucres turbinate to narrowly campanulate. Phyllaries 8–20, linear to narrowly lanceolate. Ray florets usually 0 (sometimes peripheral florets pistillate; corollas yellow, laminae rudimentary). Disc florets 20–50; corollas yellow (1 or more lobes sometimes expanded, giving appearance of laminae); anthers yellow. Cypselae brown to black, 4–7 mm, glabrous or sparsely stipitate-glandular to densely hirsute; pappi usually stramineous, rarely tawny, bristles barbellate to ± subplumose. 2n = 38, 57, 76.

Arnica angustifolia Vahl subsp. eradiata A. Gray, Proc. Acad. Nat. Sci. Philadelphia 15: 68. 1864; A. parryi A. Gray subsp. sonnei (Greene) Maguire; A. parryi var. sonnei (Greene) Cronquist

Arnica sonnei Greene, Pittonia 3: 104. 1896
Arnica discoidca radiala A. Cray, Ms.
Rootstock horizontal; stem 3-5 dm. high, densely whitevillous; basal leaves and lower stem-leaves petioled, the petioles 2-5 cm. long; blades lanceolate or ovate, dentate, 5-15 cm. long, 5-ribbcd, densely long-villous on both sides; stem-lra I a I 1 pairs, tinmiddle ones with
winged petioles, tinuppermost sessile, smaller, those of the infloR i eni t narrowly lanceolate,
small; heads 3-9, cyirir.se, involucre broadly turbinate, IS nun high, 15-20 mm. broad, glandular villous; bracts 15-20, lance linear, acuminate; ray -Mowers 10 I ', tire ligules 10 I _'
mm. long, 3-4 mm. wide, 7-9-veined; diss corollas 1 mm long; ichenes G nun long, angled,
hirsiitrand glamlular-granuliferoiis; pappus l>r i ties 9 nirn long, Light brOWU or straw-colm . .1, short -plumose.
Tvi'K l.'H Al.l I
ion Sierra '•• rada ol < aUfornia sod Nevada, and on Knxue River, ' teafsa.

Arnica parryi A. Gray, Am. Nat. 8: 213. 1874
Arnica angustifolia discoidea A. Gray, Am. Jour. Sci. II. 33: 238. hyponym. 1852. Arnica anguslifolia eradiata A. Gray. Proc. Acad. Phila. 1863: 68. 1863. Arnica eradiala A. Heller. Cat. Am. PI. 7. 1898. Arnica Parryi crinita Osterhout, Muhlenbergia 6: 47. 1910.
Rootstock horizontal; stem 3-6 dm. high, angled, villous, more or less glandular above, densely so in the inflorescence; basal leaves and those of the offsets petioled, the petioles 1-5 cm. long, the blades lanceolate or ovate, acute at both ends, 3-10 cm. long, callous-denticulate, or entire, villous on both sides; stem-leaves 3-4 pairs, the lowest ones similar to the basal leaves or with broader petioles, the uppermost lanceolate or linear-lanceolate, entire, much smaller, those of the inflorescence linear-lanceolate; heads 3-20, cymose, the lateral ones usually nodding in anthesis; involucre turbinate, 12-15 mm. high and broad, glandularhirsute; bracts 10-15, linear, acuminate; ray-flowers usually wanting, the ligules if present (var. crinita) about 8 mm. long and 3-4 mm. broad; disk-corollas 7-9 mm. long; achenes 5-6 mm. long, sulcate, sparingly hirsute or sometimes glabrous; pappus-bristles straw-colored, about 1 cm. long, barbellate.
Type locality: Mountains of Colorado.
Distribution: Mountain sides from northern New Mexico to Alberta, British Columbia, and Oregon.

Arnica parryi is a North American species of flowering plant known by the common names Parry's arnica or nodding arnica. It is native to western Canada (Yukon, British Columbia, Alberta) and the western United States as far south as Inyo County, California and McKinley County, New Mexico. It grows in temperate coniferous forests and alpine meadows in mountainous areas, primarily the Rocky Mountains, Cascades, and Sierra Nevada.

Arnica parryi is a rhizomatous perennial herb producing a single unbranched stem to heights between 10 and 60 centimeters. There are oval-shaped leaves around the base of the stem and a few pairs of longer, narrower petioled leaves above them. The leaves may approach 20 centimeters in length on larger individuals.

The inflorescence holds one to several daisylike flower heads, which nod as buds and then pull erect when the face opens. Each head has a center filled with yellow disc florets and usually no ray florets. The fruit is a cylindrical achene about half a centimeter long with a bristly pappus.