Bladderwort

These leaves and tiny bladders belong to Bladderwort, which has beautiful, small, yellow flowers (I have photos in one of my Plants of Alberta Set).

"All bladderworts are carnivorous, and capture small organisms by means of bladder-like traps. Despite their small size, these are extremely sophisticated. In aquatic species such as the Common Bladderwort U. vulgaris, the bladders are large (sometimes exceeding 5 mm in diameter and can feed on more substantial prey such as water fleas (Daphnia), nematodes and even fish fry, mosquito larvae and new tadpoles. When prey animals brush against trigger hairs connected to the trapdoor, it is released and the bladder sucks in the door and the prey, along with the water surrounding it. Once the bladder is full of water, the door closes again, the whole process taking only ten to fifteen thousandths of a second.

Bladderworts are unusual and highly specialised plants; they have no roots, and their simple structure makes distinguishing between leaf, shoot, and stem seem arbitrary. The bladder traps, conversely, are recognised as one of the most sophisticated structures in the plant kingdom." From Wikipedia.