Carex vesicaria (Bladder-sedge)

Carex vesicaria is an essentially Holarctic species of sedge known by the common names bladder-sedge and blister sedge. The dried fibers, sometimes used as thermal insulation in polar regions, are known as sennegrass, saennegrass or similar, from the plant's Bokmål name sennegras.

Distribution
This sedge is native to northern North America including most of Canada and the northern United States, down into California. It is also known from parts of Eurasia, including almost all of northern Europe. It grows in wet habitat, including many types of wetland, and areas that are soaked or submerged during the spring and dry over the summer.

Description
Carex vesicaria produces clumps of triangular stems up to about a meter in maximum height. The inflorescence is a loose cluster of flower spikes, many on peduncles. The long cylindrical inflorescence contains up to 150 developing fruits.

There are several varieties of this sedge, with a high diversity in northeastern Canada.
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