Nymphaea lutea Linnaeus var. pumila Timm, Mag. Naturk. Oekon. Mecklenburgs 2: 250. 1795; Nuphar shimadae Hayata; Nymphaea lutea subsp. pumila (Timm) Bonnier & Layens; Nymphaea pumila (Timm) Hoffmann.

Rhizomes stout, 1--3 cm in diam. Petiole 20--50 cm, pubescent; floating leaf blade broadly ovate to ovate, seldom elliptic, 6--17 × 6--12 cm, abaxially glabrous to densely pubescent, adaxially glabrous, base cordate and basal lobes remote from each other. Flower 1--4.5(--6) cm in diam. Peduncle 40--50 cm, pubescent. Sepals yellow, oblong to elliptic, 1--2.5 cm. Petals narrowly cuneate to broadly linear, 5--7 mm, apex emarginate. Anthers yellow, 1--6 mm. Stigmatic disc deeply lobed, 4--7.5 mm in diam., rays 8--13(--14). Fruit 1--2 cm in diam. Seeds brown, oblong to ovoid, 3--5 mm. Fl. May--Sep. 2n = 34.

The description of Nuphar shimadae clearly indicates that this taxon is conspecific with N. pumila ; however, it remains unclear as to which subspecies the plants in Taiwan should be referred, since no specimens were examined from that region.

Lakes, ponds. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jiangxi, Jilin, Nei Mongol, Taiwan, Xinjiang, Zhejiang [Japan, Korea, Mongolia, Russia; N Europe].