Rhizomes often constricted at branch joints to form detachable tubers. Leaves: petiole green with brown-purple stripes, stout. Leaf blade abaxially green or faintly purple. Flowers: petals white, rarely pink, elliptic to oblanceolate, outer usually with broadly rounded apex. Seeds mostly 2.8-4.5 mm.

Flowering late spring-summer. Mainly alkaline ponds, lakes, and sluggish streams and rivers, usually in very oozy sediments; 100-400 m; Man., Ont., Que.; Conn., Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Mo., Nebr., N.H., N.Y., Ohio, Okla., Pa., Vt., Wis.

This taxon, which has been included within Nymphaea odorata by some recent workers, was formerly almost universally accepted as a distinct species. In the southern parts of the range of subsp. tuberosa , where subsp. odorata is absent, subsp. tuberosa is easily distinguished morphologically from subsp. odorata . Farther north, where their ranges overlap, the distinctions break down in some populations but are maintained in others. Some western populations are probably the result of introductions. A pink-flowered form seen in southeastern Ohio appears to be derived from this subspecies.

This species is frequent to common in the lakes and sloughs of the lake area and very local south of it because its habitat is lacking. This species has generally been confused with Nymphaea odorata. Conard wrote me in 1933 that the latter species belongs to the Coastal Plain and in the interior it does not occur as far south as Indiana. On August 12, 1930, I found a rose colored form in the west side of Cheesborough Lake, Steuben County.