Nuphar ulvacea
Publ. Field Columbian Mus., Bot. Ser. 8: 311. 1931 (as ulvaceum).
Rhizomes 2-5 cm diam. Leaves floating or submersed; petiole terete. Leaf-blade abaxially and adaxially green, lanceolate to ovate, 15-25 × 8-10 cm, ca. 2.5 times as long as wide, sinus less than 1/3 length of midrib, lobes often overlapping; surfaces glabrous. Flowers 2-3 cm diam.; sepals 6-9, abaxially green to adaxially yellow toward base; petals oblong, thick; anthers 2-5 mm, slightly longer than filaments. Fruit green, nearly globose, 1.5-2.5 × 1.5-2.5 cm, strongly ribbed, slightly constricted below stigmatic disk; stigmatic disk green, 11-18 mm diam., undulate; stigmatic rays 9-16, ± elliptic, terminating within 1 mm from margin of disk. Seeds 3.5-4 mm.
Phenology: Flowering spring–early fall.
Habitat: Blackwater rivers and streams
Elevation: 0-100 m
Discussion
Of conservation concern.
Nuphar ulvacea is probably better treated as a subspecies. Gulf coast plants intermediate between N. ulvacea and N. advena, which have been treated as Nymphaea [Nuphar] chartacea, are treated under N. advena.
Selected References
None.
Lower Taxa
"thick" is not a number.