Description
Flat-leaved Bladderwort is a perennial aquatic herb with submerged stems, leaves, bladders, overwintering buds, and emergent flowers. The plants have slender stems with numerous, crowded, finely dissected leaves. The leaves are mostly 0.5-2 cm long, flattened, and have several linear divisions all of about the same width and abruptly tapering or blunt at the tip. Bladders, which trap small aquatic animals for the plant's nourishment, are borne on separate specialized branches. Two to four small snapdragon-like flowers are borne on short pedicels on a 4-15 mm long, erect, leafless scape which holds them out of the water. Flowers have an inconspicuous, two-lobed calyx and a bright yellow, two-lipped corolla. The lower corolla lip is usually 4-8 mm long; underneath, it has a spur which is half or more as long as the entire lip; above, it has a prominent raised palate. The upper corolla lip is about half as long as the lower lip. The mature fruits are few seeded, dry, globular capsules borne on erect pedicels.
Diagnostic Characteristics
Distinguished from Utricularia vulgaris by having leaves which are initially 3-parted at the base with flattened segments. Distinguished from U. minor by having bladders borne on separate specialized branches rather than among the leaves, by having flowers with the lower lip with a long spur and a prominent palate, and by mature fruits on erect rather than curved pedicels.
From CNHP Wetland Guide 2012: Main Characteristics:
·Spur about as long as the lower corolla lip; corolla deep yellow
·Tips of leaf segments usually slightly rounded; bristles of leaf margins not on teeth
Habitat
This species is found in shallow water, less than 1 meter deep, at elevations ranging from 1,200 to 2,700 meters (Rice, 2022).