Nuphar sagittifolia is probably best treated as a subspecies. Plants intermediate between it and N . advena are treated under N . advena . The clinal variation pattern between the two taxa is apparently maintained via selection by vernalization (C. E. DePoe and E. O. Beal 1969; E. O. Beal and R. M. Southall 1977).

This taxon is the Cape Fear spatterdock of the aquarium trade.

Rhizomes 2-2.5 cm diam. Leaves floating or submersed; petiole terete. Leaf blade abaxially and adaxially green, linear to lanceolate, 15-30(-50) × 5-10(-11.5) cm, 3-5 times as long as wide, sinus less than 1/3 length of midrib, lobes usually divergent and forming V-shaped angle; surfaces glabrous. Flowers 2-3 cm diam.; sepals 6, abaxially green to adaxially yellow toward base; petals oblong, thick; anthers 3-5 mm, barely or not at all longer than filaments. Fruit green, ovoid, 3-3.5 × 2-3 cm, smooth basally, strongly ribbed toward apex, slightly constricted below stigmatic disk; stigmatic disk green, 14-18 mm diam., nearly entire; stigmatic rays 10-14, linear, mostly terminating 1-2 mm from margin of disk. Seeds 4-5 mm.

N.C., S.C., Va.

Flowering mid spring-early fall.

Freshwater streams, rivers, ponds, and lakes of coastal plain, extending to freshwater tidal areas; of conservation concern; 0-50m.

Nymphaea sagittifolia Walter, Fl. Carol., 155. 1788; Nuphar lutea (Linnaeus) Smith subsp. sagittifolia (Walter) E. O. Beal

Nuphar sagittifolia, common name arrow-leaved water-lily or Cape Fear spatterdock, is a plant species known only from North Carolina, South Carolina, and Virginia. It is aquatic, found in lakes, ponds, and slow-moving rivers in the coastal plains of those states. It is also sold in pet shops as greenery to grow in aquaria and water-gardens.

Nuphar sagittifolia is a perennial herb with rhizomes buried in the mud below the water. Leaf blades either float on the surface of the water or are submerged beneath it. Petioles are terete (round in cross-section). Leaves are 3-lobed and sagittate (arrow-shaped or V-shaped), the tips of the lobes sometimes rounded. Flowers are green and yellow, 2–3 cm (1–1 in) in diameter, usually held above the surface of the water.