Flower:

Raceme bearing 2 to 8 (more commonly 2 to 4) bright yellow, snapdragon-like flowers at the top of a naked maroon to green stem emerging from the water. The lower lip is ¼ to 1/3 inch long and slightly longer and rather broader than the upper lip. At the base of the lower lip is an inflated pouch; red venation on the lower lip and pouch is generally not present. A thick, curved spur is present below the lower lip that is a little shorter than the lower lip.

The 2 small sepals behind the flower are green to yellowish-green, about equal in size, egg-shaped with a blunt tip. Flower stalks are green; at the base of the stalk is a lance-oblong, leaf-like bract.

Unique to this species, self-pollinating (cleistogamous) flowers commonly develop on short stalks near the base of the raceme's stem and are usually submerged.

Leaves and stems:

Leaves are up to ¾ inch long, very delicate and float in water or are integrated within the peat or muck. Leaf branches are alternate and forked 5 to 10 times. Bladders are present on most leaves. Turions (overwintering vegetative buds) form at branch tips in the late summer to early fall. Stems are up to 10 inches long and sparingly branched.

Fruit:

Fruit is a round capsule.

Notes:

Hidden-fruit Bladderwort, a more common plant in the northeastern U.S., is quite rare in Minnesota. It wasn't discovered and collected in the state until 2004 and was listed as a Threatened species in 2013. U. geminiscapa can easily be distinguished from the other 7 Utricularia species in MN by the cleistogamous flowers. It is most likely to be confused with Common Bladderwort (U. vulgaris), which has rather larger flowers, up to ¾ inch, and typically more flowers per raceme. The leaves of the two species are similar and vegetative fragments can be very difficult to distinguish. Although the commonly held view is that the bladders of bladderworts are for capturing and digesting microorganisms that provide the plant with nutrients, bladders more often have been observed to contain communities of microorganisms (bacteria, algae, and diatoms) living in the bladders, not as prey, suggesting that the bladders may also, and perhaps more importantly, serve to establish mutually beneficial relationships with some microorganisms.