Arnica discoidea


Pl. Hartw., 319. 1849.

Common names: Rayless arnica
Synonyms: Arnica alata Rydberg Arnica cordifolia var. eradiata A. Gray Arnica discoidea var. alata (Rydberg) Cronquist Arnica discoidea var. eradiata (A. Gray) Cronquist Arnica parviflora
Treatment appears in FNA Volume 21. Treatment on page 375. Mentioned on page 367.

Plants 15–60 cm. Stems mostly simple or distally branched. Leaves 3–7 pairs, sometimes crowded at stem bases (basal leaves often persistent on sterile rosettes); petiolate (petioles narrow, 1.5–8 cm, often broadly winged on distal reduced leaves); blades usually ovate to broadly lanceolate, seldom subcordate, 2–12 × 1–7 cm, margins usually serrate to coarsely dentate or crenate, rarely subentire, faces glabrate to pilose, stipitate-glandular. Heads 3–10(–30; erect). Involucres turbinate-campanulate. Phyllaries 8–15, ovate-lanceolate to narrowly lanceolate. Ray florets usually 0 (corollas of peripheral florets rarely dilated, resembling rays). Disc florets 20–50; corollas yellow; anthers yellow. Cypselae dark gray, 6–8 mm, hirsute (hairs duplex) and stipitate-glandular; pappi white, bristles usually barbellate, sometimes subplumose. 2n = 38, 57, 76.

Phenology: Flowering May–Jul.
Habitat: Chaparral, oak and pine forests
Elevation: 100–1500 m



Calif., Nev., Oreg., Wash.


Selected References


Lower Taxa

... more about "Arnica discoidea"
Steven J. Wolf +
Bentham +
Rayless arnica +
Calif. +, Nev. +, Oreg. +  and Wash. +
100–1500 m +
Chaparral, oak and pine forests +
Flowering May–Jul. +
Pl. Hartw., +
Arnica alata +, Arnica cordifolia var. eradiata +, Arnica discoidea var. alata +, Arnica discoidea var. eradiata +  and Arnica parviflora +
Arnica discoidea +
species +