Perennial or annual herb, 30-100 cm, erect, usually ± branched to middle, often with ± repent vegetative branches at base, blackening when dry. Stems usually thick, hollow, glabrous. Leaves glabrous, rarely uppermost glandular-pubescent, lamina 30-70 x 10-25 mm, lower shortly petiolate , ovate, elliptic or oblong, obtuse, upp'er sessile, broadly lanceolate, ± acute, base of middle and upper cordate-amplexicaul, often subauriculate and enlarged, of uppermost sometimes slightly cuneate; margin serrulate, denticulate to subentire. Racemes 6-25 , 20-40-flowered with 2-7 pedicels per cm in fruit, glabrous or ± glandular-pubescent with 0,05-0,15 mm glandular hairs . Bracts linear to lanceolate, acute. Fruiting pedicels 4-7 mm, 1,5-3 x bracts, suberect, arcuate- erect to subpatent. Calyx 2-2,5 mm in flower. Corolla lavender to pale blue or pale lilac, 4-6 mm diam. Style 1,5-2 mm. Capsule orbicular, inflated, 3-3,5 x 2,5-3,2 mm, equalling calyx or slightly shorter, apex not or only very slightly emarginate, glabrous or sparsely shortly glandular-pubescent. Seeds 40-70, elliptic to suborbicular, plano-convex, 0,5-0,6 x 0,4-0,5 mm, with dot-like chalaza. 2n= 18 or 36. Fl. 3-9. Streams, ditches, banks, springS, swamps, wet meadows, s.I.-2350 m.
V. anagallis-aquatica thus now comprises four subspecies:
subsp. lysimachioides M.A. Fischer,
subsp. michauxii Elenevsky and
subsp. oxycarpa Elencvsky.