American golden-saxifrage, water-mat or -carpet, dorine d’Amérique

Stolons white or tan, 0.3-1 mm diam., glabrous. Flowering stems repent, decumbent, or ascending, branching in distal 1/4-1/2, 4-30 cm, glabrous. Leaves opposite, sometimes alternate distally, membranous. Stolon leaves: petiole 1-4 mm, glabrous; blade ovate to depressed-ovate, round, or flabellate, 2.5-15 × 2-10(-20) mm, base attenuate to cordate, margins subentire or 5-7(-9)-crenate or -crenulate, not purple-spotted, glabrous, surfaces glabrous abaxially and adaxially. Cauline leaves 4-9; petiole absent or 0.1-4 mm, glabrous; blade ovate to depressed-ovate, round, or flabellate, 2.5-15 × 2-10(-20) mm, base attenuate to cordate, margins 5-7(-9)-crenate or -crenulate, glabrous, surfaces glabrous abaxially and adaxially. Inflorescences terminal or axillary solitary flowers or 2-10-flowered, open cymes; bracts green, not purple-spotted, foliaceous, ovate to flabellate, 2-7 × 2-7 mm, margins subentire or 5-7-crenate or -crenulate. Pedicels absent or 0.1-0.8 mm. Flowers: hypanthium green, not purple-spotted, turbinate, 0.9-1.8 × 1.4-2.6 mm, glabrous; sepals spreading to erect, green, greenish yellow, or greenish red, not purple-spotted or purplish brown-spotted distally, broadly triangular or broadly ovate to nearly round, 1.3-1.8 × 0.9-1.6 mm, apex obtuse to rounded; nectary disc conspicuous, green or purple, 8-lobed; stamens 4-8, 0.5-0.9 mm; anthers purple, red, or orange, 0.2-0.3 × 0.4-0.5 mm; styles 0.2-0.6 mm. Seeds 6-16, dark brown, spheroid to ovoid, (0.5-)0.6-0.8 mm, puberulent. 2n = 18, 24.

Flowering Mar-Jul. Marshy ground, streamsides, seeps, springs, swampy woods; 0-1500 m; N.B., N.S., Ont., P.E.I., Que.; Conn., Del., Ga., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, R.I., S.C., Tenn., Vt., Va., W.Va., Wis.