Manchu tuber gourd, red hailstone, thladianthe douteuse Manchu tuber gourd, red hailstone, thladianthe douteuse

Leaf blades 5–10 × 4–9 cm, base cordate, apex short-acuminate, surfaces hirsutulous. Inflorescences: peduncle 5–15 mm. Flowers: hypanthium 2–4 mm; sepals recurving, 12–13 mm; petals ca. 25 mm, apex acute. Pepos 4–5 cm, surface with 10 obscure furrows. 2n = 18.

Flowering Jun–Sep. Roadsides, thickets, pastures, waste places; 10–200 m; introduced; Man., Ont., Que.; Ill., Mass., N.H., N.Y., Wis.; Asia (China, Russia); introduced also in South America (Ecuador), Europe, elsewhere in e Asia (China, Japan), Pacific Islands (Galapagos Islands).

Thladiantha dubia is characterized by its ovate-cordate, unlobed leaves; relatively large, solitary flowers with narrow, recurving sepals, campanulate corollas, yellow petals, usually with recurving apices; and pendulous, hirsute-villous, orange-red fruits. It is grown as an ornamental, especially for its large, bell-shaped flowers and brightly colored fruits. Few populations are apparently outside of cultivation at present, but even staminate plants are potentially invasive because of the spread by tubers.