Phtheirotheca Maximowicz ex Regel.

Herbs, perennial, deciduous, glabrous. Rhizome creeping, stout, nodose, with numerous fibrous roots. Aerial stem erect. Leaves alternate, 2 or 3 × ternately compound, broadly ovate in overall outline; petiole short or leaves sessile; pinnules petiolulate or sessile, ovate, obovate, or broadly lanceolate, undivided or lobed, venation pinnate or palmate, margin entire. Inflorescences terminal, compound cymes. Flowers 3-merous; bracteoles 3 or 4, sepaloid, caducous. Sepals 6, petaloid, yellow, red, purple, or green. Petals 6, fan-shaped or obovate, nectary-like. Stamens distinct; anthers dehiscing by 2 apically hinged flaps; pollen prolate, 3-colporate, exine reticulate. Ovary bladderlike; placentation basal; styles eccentric. Fruit not developing, ovary wall soon rupturing and seed coat becoming fleshy and fruitlike. Seeds 2, raised on elongating stalk, naked at maturity, globose; seed coat tunic-blue, fleshy, glaucous. x = 8.

Three species: North America and E Asia; one species in China.

(Authors: Ying Junsheng (应俊生 Ying Tsun-shen); David E. Boufford, Anthony R. Brach)