Perennial, submerged, freely suspended, insectivorous, aquatic herb; stolons robust, to several m long, distinctly flattened, to 4 mm wide, with fasciculate branches. Photosynthetic organs pinnate many times, +/- broadly ovate in outline, to 17 cm long, somewhat dimorphic, some with more traps and fewer segments; insect traps borne laterally near base of penultimate segments. Racemes erect, simple, 7-40 cm long; flowers 3-20, congested at anthesis, later spaced on rachis; scape with 1 or 2 scales below lowest flower; bracts subtending flowers broadly ovate to orbicular; pedicels erect, 4-10 mm long, becoming reflexed in fruit and to 16 mm long; calyx lobes 2, subequal, broadly ovate, the lower lobe sometimes toothed. corolla yellow, sometimes with purple veins, bilabiate, the upper lip +/- orbicular, ca twice as long as calyx lobes, the lower lip larger, gibbous, the margin entire or emarginate, the spur conical and ca two-thirds as long as lower lip, its inner surface with stalked glands along central vein; stamens 2; filaments curved; ovary subglobose; ovules few; style short, distinct; stigma bilabiate. Capsules globose, to 8 mm diam, sparsely glandular, indehiscent; seeds 4-12, 2-2.5 mm diam, lenticular, with a narrow wing. Shattuck 369.