Flatleaf Bladderwort - Utricularia intermedia
State Rank Reason (see State Rank above)
Only known from a few occurrences in the western half of the state.
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.
Flowering in late July.
Distinguished from U. macrorhiza 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.
Circumboreal; in North America occurs from Alaska to eastern Canada and south to California, northwestern Wyoming, North Dakota, Illinois, and Pennsylvania.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Shallow water of peatlands in the valley to montane zones.
Ecological Systems Associated with this Species
- Additional ReferencesLegend: View Online Publication
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- Lesica, P. 1994. The distribution of plant community diversity associated with glacial wetlands in the Ovando Valley, Montana. [Unpublished report.] The Nature Conservancy, Montana Field Office, Helena. 26 pp.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.