Utricularia intermedia (Flat-Leaved Bladderwort) - photos and description

Utricularia intermedia

Utricularia intermedia

Utricularia intermedia

Utricularia intermedia

Utricularia intermedia
Leaves shown in above photo

Utricularia intermedia
Bladders in this species grow on stem by themselves - with no leaves

General: Aquatic plant found in shallow, muddy pools in forest bogs, often creeping in the mud as in the plant above. Carnivorous plant which captures its prey via tiny bladders submerged underwater. Bladders approximatley 3 mm in diameter. From the book Carnivorous Plants by Randall Schwartz:

The bladder, or trap, is an oval balloon with a double-sealed, airtight door on one end. When the door is closed, the bladder expels water through its walls, creating a partial vacuum inside.

Jutting out near the door is the trigger. Sometimes forked or branched, sometimes single, the device is always deadly. The instant an unsuspecting prey touches the trigger, the door opens. The vacuum inside causes an immediate suction and the victim is gulped up by the plant.

Flowers: Flowers single or in a raceme of up to 5 flowers. Flowers are yellow and have a large, flat lower lip. We measured a flower to 14 mm across). Flowers early July.

Leaves: Leaves numerous in submerged branches, they are divided several times into thread like segments.

Height: We measured a flowering scape at 11 cm long.

Habitat: Bogs in the boreal forest.

Abundance: Common.

Origin: Native.

How to identify this species: Distinguishing characteristic of this species is that the bladders are not intermixed among the leaves, but are found rather on leafless branches.

When and where photographed: The above photos were taken in acidic bogs in June 29th, June 30th, and July 20th in boreal forest in central Saskatchewan about 350 km north of our home in Regina, SK.