Nuphar sagittifolia (Walter) Pursh. Section: Astylus. Narrowleaf Pondlily, Bonnets. Phen: Apr-Oct. Hab: Blackwater streams, rivers, and lakes, acid-water ponds, in swift, sluggish, or stagnant water, extending downriver into freshwater tidal areas. Dist: Endemic to our area: e. VA south to ne. SC, very conspicuous and locally abundant on shallow bars along rivers such as the Northeast Cape Fear, Black, and Waccamaw, and forming dense colonies in Lake Waccamaw.

Origin/Endemic status: Endemic

Taxonomy Comments: Apparent hybrids with N. advena have been named Nuphar ×interfluitans Fernald. The submersed leaves have somewhat the texture and appearance of a thin leaf lettuce or the marine alga Ulva. This species appears to be closely related to N. ulvacea (Miller & Standley) Standley of blackwater rivers of Panhandle FL, another phytogeographic connection between se. NC and Panhandle FL. DePoe & Beal (1969) and Beal & Southall (1977) argue that this taxon and N. advena intergrade clinally, with N. advena inland and N. sagittifolia in the outer Coastal Plain, and that the two taxa are maintained by water temperatures. This ignores the fact that the two taxa often occur in close proximity to one another in both the inner and outer Coastal Plain; moreover, N. sagittifolia maintains its characteristics as stable in cultivation inland. I prefer to treat these taxa as species, with rare to uncommon hybridization or introgression. Moreover, molecular data suggest that N. sagittifolia is more closely related to the boreal N. variegata than to N. advena (Padgett 2007).

Synonymy: = AqW, C, FNA3, K3, K4, Va, Padgett (2007); = Nuphar lutea Sm. ssp. sagittifolia (Walter) E.O.Beal – K1; = Nuphar luteum (L.) Sibth. & Sm. ssp. sagittifolium (Walter) E.O.Beal – GW2, RAB, Beal (1956); = Nuphar sagittifolium – F, G, orthographic variant; = Nymphaea sagittaefolia Walter – S13; = Nymphaea sagittifolia Walter – S

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Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: OBL
• Northcentral & Northeast: OBL

Heliophily: 8