Aquatic herb, perennating by winter buds (turions). Stolons 2 or 3 from the base of the scape, filiform, terete, glabrous, up to 50 cm. long or more, 0.5–1.5 mm. thick; internodes 3–10 mm.; rhizoids few (2–4) from the scape-base, capillary, 1–2 cm. long. Leaves very numerous, 2-branched from the base, each branch 1–5 cm. long, ovate to lanceolate in outline, pinnately branched; pinnae alternate, repeatedly dichotomously forked; ultimate segments capillary, setulose. Traps usually numerous, lateral on the leaf-segments just above the point of bifurcation, obliquely ovoid, stalked, 1–2 mm. long; mouth lateral, oblique; upper lip with 2 slender ± branched hairs; lower lip with a variable number of simple hairs. Inflorescence erect, up to 15 cm. high; scape usually straight at anthesis but becoming very flexuous, 1–2 mm. thick, smooth and glabrous; flowers 4–6, ± congested at anthesis, inflorescence-axis elongating after anthesis; scales 1–2(3), a short distance below the lowermost flower, similar to the bracts; bracts basifixed, orbicular, ± 3 mm. long, decurrent; bracteoles absent; pedicels filiform, 1–2 cm. long, erect at anthesis, elongating and spreading or deflexing after anthesis. Calyx-lobes subequal, ovate, ± 3 mm. long; upper lobe apex rounded, hyaline; lower lobe truncate or emarginate. Corolla pale yellow, ±15 mm. long; upper lip orbicular or broadly ovate, truncate, 2–3 times as long as the upper calyx-lobe; lower lip oblate or reniform, ± as long as the upper lip and up to twice as wide; palate raised, gibbous; spur stout, conical, slightly curved, obtuse, usually shorter than the lower lip, with shortly stalked glands on the inner adaxial surface only. Filaments filiform; anther-thecae confluent. Ovary globose, minutely lepidote; style distinct, almost as long as the ovary; stigma lower lip semi-orbicular, margin ciliate, upper almost obsolete. Capsules apparently never produced.