Common Leopardbane

Plants 20–80 cm. Stems simple. Leaves 2–4(–6) pairs, nearly all basal; sessile; blades (with 3, 5, or 7 prominent, subparallel veins) broadly elliptic, ovate, or rhombic, 4–15 × 1.5–8 cm, margins mostly entire, apices mostly obtuse, faces hirsute and stipitate-glandular (cauline leaves 0 or 1–2, distalmost often alternate, much reduced). Heads 3–20. Involucres campanulate. Phyllaries 12–18, narrowly ovate. Ray florets 10–16; corollas yellow. Disc florets: corollas yellow; anthers yellow. Cypselae dark gray to dark brown, 5–7 mm, glabrous or sparsely stipitate-glandular; pappi white, bristles barbellate. 2n = 38.

Doronicum acaule Walter, Fl. Carol., 205. 1788

Arnica acaulis (Walt.) B. S. P. Prel. Cat. N. Y.
Doronicum acaulc Walt. Ft. Car. 205. 1788. Doronicum nudicaule Michx. Fl. Bor. Am. 2: 121. 1803. Arnica Clavtoni Pursh, Fl. Am. Sept. 527. 1814. Arnica nudicaulis Nutt. Gen. 2: 164. 1818._ Arnica brevicaulis Raf. New. Fl. 2: 23. 1837.
A perennial, with a short crown and a cluster of fibrous roots; leaves mostly basal, tufted, oval or ovate, obtuse at the apex, subsessile, 5-7-ribbed, entire or sinuate, 5-15 cm. long, 3-7 cm. broad, hirsute and glandular-punctate on both sides, less densely so beneath; stem scapiform, 3-6 dm. high, hirsute-villous; stem-leaves usually reduced, 1-3 pairs, elliptic or oblong, usually less than 5 cm. long, entire or the larger ones denticulate, sessile, sometimes slightly clasping, those of the inflorescence linear, often alternate; heads 1-10,' usually irregularly cymose; involucre turbinate-campanulate, 10-12 mm. high, 12-15 mm. broad, hirsute; bracts 12-18, lanceolate, long-acuminate; ray-flowers 12-15, the ligules 10-15 mm. long, 3-4 mm. wide, 3or 4-toothed at the apex, 7-9-veined; disk-corollas 7 mm. long; achenes 4—5 mm. long, sulcate, sparingly hispidulous on the ribs; pappus-bristles white or straw-colored, 1 cm. long, barbellate.
Type locality: Carolina.
Distribution: Open woods, from Pennsylvania to middle Florida.

Arnica acaulis is a North American species of plants in the sunflower family, known by the common name common leopardbane. It is native to the southeastern and east-central parts of the United States, from Alabama and Florida north to New Jersey and Pennsylvania.