Plants perennial, glabrous or distinctly papillose especially on veins of leaf blades abaxially, with fusiform, vertical rootstock. Stems erect, often flexuous in distal part, branched in distal 2/3, occasionally almost from base, 20–60(–70) cm. Leaves: ocrea deciduous or partially persistent at maturity; blade oblong to ovate-oblong, sometimes broadly lanceolate or panduriform, contracted near middle or proximally, 4–10(–15) × (2–)3–5 cm, less than 4 times as long as wide, base normally truncate or weakly cordate, occasionally rounded, margins entire, flat or undulate, rarely slightly crisped, apex obtuse or subacute. Inflorescences terminal, occupying distal 2/3 of stem or more, usually lax and interrupted, broadly paniculate, branches usually divaricately spreading, forming angle of 60–90° with 1st-order stem. Pedicels articulated in proximal 1/3 or occasionally near middle, thickened, not filiform, 2–5(–6) mm, articulation distinctly swollen. Flowers 10–20 in rather dense whorls; inner tepals ovate-triangular, deltoid, or oblong-deltoid, 3–6 × 2–3 mm (excluding teeth), normally ca. 1.5 times as long as wide, base truncate, margins usually distinctly dentate, rarely subentire, apex obtuse to subacute, straight, teeth 2–5(–9), normally on margins at each side, narrowly triangular, 0.3–2.5 mm, longer or shorter than width of inner tepals; tubercles (1–)3, equal or unequal, usually verrucose (warty). Achenes dark reddish brown to almost black, 2–2.8 × 1.3–2 mm. 2n = 20.