Ranunculus acraeus

Detailed description

Robust, summer-green, rhizomatous herb, up to 40 cm high, forming patches up to 1 m across. Rhizomes numerous, stout, 10–12 mm diameter, regularly branched. Lamina 60–75 × 75–130 mm, broadly reniform or broadly orbicular, grey to grey-green, sparsely covered with pilose hairs, glabrate or glabrous, divided into 3 primary segments; margin crenate, teeth 2–9 mm long, broadly obovate, oblong to broadly oblong, apices obtuse, margin red; petiole 50–250 × 5–9 mm, fleshy, terete; sheath 15–40 mm, moderately to densely covered with pilose hairs. Inflorescence 80–400 × 5–14 mm, yellow-green to green, terete, with 1–6 flowers, each flower subtended by a leafy bract. Bracts similar to leaves, sessile, smaller toward distal flowers. Peduncles glabrous. Flowers 40–50 mm diameter. Sepals 6–7, 20–22 × 8–11 mm, yellow-green to light green, oblong, oblong-elliptic or broadly elliptic, hairy on abaxial surface, glabrous on adaxial surface. Petals 16–27, 22–27 × 5–13 mm, yellow, narrowly to broadly oblanceolate, apex obtuse, nectary a simple pit. Stamens 110–139, glabrous; filament 1.6–8.5 × 0.7–1.4 mm, translucent; anthers 1.8–2.8 mm long, cream. Carpels 126–171. Achenes 6.4–7.3 × 2.7–3.4 mm, yellow-brown; beak curved to ventral side, laterally compressed, tapering toward a point at apex.