Arnica cernua Howell

Plants 10–30 cm. Stems (often reddish purple) mostly simple. Leaves 3–4 pairs, mostly cauline (basal often persistent on sterile rosettes); petiolate (petioles usually narrow, proximalmost sometimes broadly winged); blades (often reddish purple) usually elliptic to ovate, sometimes subcordate, 1.5–8 × 1.5–4 cm (often relatively thick, nearly succulent), margins usually entire or serrate, sometimes crenate or slightly lobed, apices acute to rounded, faces glabrous or scabrous. Heads usually 1, sometimes 2–3 (often nodding in bud). Involucres campanulate-turbinate. Phyllaries 8–14, ovate to broadly lanceolate. Ray florets 5–10; corollas yellow to slightly orange. Disc florets: corollas yellow; anthers yellow. Cypselae dark gray, 6–8 mm, sparsely to densely hirsute (hairs duplex); pappi white, bristles usually barbellate, sometimes subplumose. 2n = 38.

Arnica chandleri Rydberg

Arnica cernua Howell, Fl. N. W. Am. 373. 1900
Rootstock slender; stem 3-4 dm. high, sulcate, sparingly puberulent below, densely so and glandular-granuliferous on the upper part of the peduncles; petioles of the leaves of the offsets about 3 cm. long; blades elliptic or oval, 2.5-3 cm. long, 1-3 cm. wide, entire, sparingly puberulent; basal leaves short-petioled; blades 1.5-3.5 cm. long, oval, obtusely dentate, puberulent; stem-leaves 2 or 3 pairs, the lower similar to the basal leaves but often with larger blades, the middle ones with wing-margined petioles, the uppermost sessile, lanceolate, entiremargined; heads usually solitary; involucre round-campanulate, 13 mm. high, 15 mm. broad, short-villous and glandular-puberulent ; bracts about 10, linear or lanceolate, acutish or obtuse, ray-flowers about 10, the ligules about 15 mm. long and 5 mm. broad; tube of the disk-corollas 4 mm. long, the throat 5 mm. long, the lobes ovate; achenes 8-9 mm. long, sparingly hirsute; pappus-bristles white, 8 mm. long, barbellate.
Type locality: Coast Range, near Waldo, Oregon. Distribution: Southwestern Oregon.

Arnica chandleri Rydberg, sp. now
Rootstock slender; stem 1.5-2 dm. high, slender, purplish, sparingly villous; petioles of
the basal leaves 1-3 cm. long; blades rounded-obovate, coarsely dentate, 5-ribbed, thick,
glabrous beneath, sparingly villous or glabrate above, villous-ciliate on the wing-margined
petioles; stem-leaves 2 or 3 pairs, the lowest pair petioled, the blades ovate, about 3 cm. long,
dentate, the upper 1 or 2 reduced, sessile, oblanceolate or linear; heads solitary; peduncle 3-4
cm. long; involucre turbinate, about 1 cm. high and 12 mm. broad, villous and glandular-
puberulent; bracts about 10, oblong-lanceolate, acute; ray-flowers 8-10, the ligules orange,
about 12 mm. long and 3 mm. broad, deeply 3-toothed; disk-flowers 7-8 mm. long; lobes ovate;
achenes 5 mm. long, hirsute; pappus-bristles white, 7 mm. long, barbellate.
Tvpe collected on the Hupi Indian Reservation, California, June 1901, H. P. Chandler 1298 (herb. N. Y. Bot. Gard.).

Arnica cernua (lat. Arnica cernua) - mürəkkəbçiçəklilər fəsiləsinin öküzotu cinsinə aid bitki növü.

Arnica cernua is a species of arnica known by the common name serpentine arnica. It is native to the Klamath Mountains of northern California and southern Oregon, where it is a member of the serpentine soils flora.

This is a perennial herb growing one or more green to purplish stems up to about 30 centimeters tall. There are 3 or 4 pairs of leaves on long petioles. The blade is oval to spade-shaped and may be several centimeters long. The inflorescence contains one or more hairy, glandular, daisylike flower heads, each with a center of yellowish disc florets and a fringe of yellow ray florets which approach 3 centimeters in maximum length.

The fruit is a cylindrical achene about 7 millimeters long which is covered in stiff hairs and has a white pappus at one end.

Arnica cernua là một loài thực vật có hoa trong họ Cúc. Loài này được Howell mô tả khoa học đầu tiên năm 1900.