Common Name: Slough Sedge

General Information

Carex obnupta is a perennial plant with a robust, stout creeping rhizomatous rootstock. It produces dense clusters of grass-like leaves, spreading at the roots to form dense colonies around 60 - 150cm tall[].
The plant is harvested from the wild for local use as a source of materials. Baskets made using this plant are often sold in local markets.
Carex obnupta is densely rhizomatous, spreading freely at the roots, and can be invasive in pastures or wet meadows[]. In muddy areas this species can grow as a dense, single-species stand[].
Carex obnupta is widespread with some stable populations and does not face any major threats. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2016)[].

Known Hazards

None known

Botanical References

Range

Western N. America - British Columbia, Washington, Oregon, California

Habitat

Wet, shallow, inundated woods, meadows, roadside ditches, coastal swamps, lakeshores, bogs, marshes, and riverbanks; at elevations up to 900 metres[]

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Perennial
Height	1.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

The plant requires wetlands in which to grow healthily, preferring freshwater conditions but also tolerant of some salinity[].
This species occasionally hybridizes with Carex nudata[].

Edible Uses

We have no specific information for this species, but the young shoots and tender leaf bases of almost all species in this genus have a sweet flavour[]. They furnish a tasty nibble and make an excellent emergency food in the wild since they are widely available[].

Medicinal

None known

Agroforestry Uses:

The growing plant provides erosion control and streambank stabilization. The dense swards of slough sedge provide sediment retention and nutrient uptake, thus contributing to water quality improvement[].
Carex obnupta is densely rhizomatous, spreading freely at the roots, and can be invasive in pastures or wet meadows[]. Which, of course, makes it an ideal pioneer species when restoring natural wetlands[].

Other Uses

The leaves are used for both wrapping and twining in 'grass' baskets that are well known and widely marketed by Nitinaht and Nootka women even today (Turner et al. 1983'.
"Grass" baskets are created using "three-cornered grass" (Scirpus pungens) for the basket bottom and ribs, slough sedge for the wrapping, and the top rim is made of the inner bark of western red cedar (Thuja plicata). The baskets usually have tightly fitting, convex lids of the same weave, and usually both basket and lid have designs of whales, birds, canoes, or geometric patterns woven with dyed strands of twining materials[].

The leaves of most species in this genus can be used to make a soft, insulated bedding for sleeping on when camping etc[].

Propagation

Seed - sow in situ in the spring in a moist soil in light shade. If seed is in short supply it can be sown in a cold frame and be planted out in the summer. The seed usually germinates in 2 - 6 weeks at 15°c[]. Plants started from seed tend to stay diminutive for over a year, with plant leaves remaining stunted and fragile for a considerable period of time[].
Division in spring[]. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the summer or following spring.