+-----------------------------------------------------------------------+
| ## Slough sedge {#slough-sedge .Title-Header}                         |
+-----------------------------------------------------------------------+
| *Carex obnupta* Bailey                                                |
+-----------------------------------------------------------------------+
| Plant Symbol = CAOB3                                                  |
+-----------------------------------------------------------------------+

####### *Contributed By: USDA NRCS Idaho Plant Materials Center & the National Plant Data Center*

# Alternate Names

Tall basket grass, sedge

**Uses**

*Ethnobotanic*: The leaves of *Carex obnupta*, are used for both
wrapping and twining in the \"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 Nitinaht believed that picking \"grasses\" for baskets and mats
(such as, *Carex obnupta* and *Scirpus pungens*) causes fog. The
fisherman were always getting annoyed with the women who harvested these
materials, because they were always making it foggy. It is said that
Hesaquiat men shaved with this \"grass\" because the edges are so sharp.
There is a saying in Hesaquiat which means \"you\'re just like *citapt,*
(*Carex obnupta*) you never change,\" because *citapt* is always the
same and never seems to change in appearance.
![](media/image2.jpeg){width="2.3958333333333335in"
height="4.094444444444444in"}

*Erosion Control*: *Carex obnupta* provides erosion control and
streambank stabilization. The dense swards of slough sedge provide
sediment retention and nutrient uptake, thus contributing to water
quality improvement. Emergent wetland plant communities dominated by
slough sedge provide the following hydrologic functions:

-   maintaining river or stream meander patterns;

-   providing a broad, shallow plain where streamflow velocities slow
    and sediment deposition occurs;

-   stormwater abatement;

-   a mixing zone where brackish and freshwaters meet; and

-   nutrient-rich habitat for aquatic organisms, fish, waterfowl, and
    predators such as otter, bald eagles, herons, and raccoons to feed.

*Wildlife*: The lens-shaped seeds of sedges are eaten by many kinds of
wildlife. Birds known to eat sedge seeds include coots, ducks (such as
wood ducks, canvasbacks, mallards, pintails, teal, shoveler), marsh
birds and shorebirds (dowichers, rails, and sandpipers), upland
gamebirds (grouse, pheasant, and wild turkey), and songbirds (house
finch, junco, sparrow, and towhee). Waterfowl and ducks eat sedge seeds
frequently in small to fair amounts. In addition to providing food for
many wildlife species, sedges are also valuable for cover. Frequently
they provide nesting cover for ducks, and their tufted growth furnishes
concealment and bedding for other animals. Beavers, otters, muskrats and
minks make their way through the sedges as they go to and from the
water.

*Invasive Potential*: This plant is densely rhizomatous, and can be
invasive in pastures or wet meadows.

# Description

*General*: Sedge Family (Cyperaceae). Slough sedge is a robust sedge
that grows 60-150 cm tall; this densely tufted, grasslike plant has
stout, creeping rhizomes. The leaves are w-shaped, coarse, with the
margins rolled under. The 4-8 cylindrical flower spikes are very large
and long (5-12 cm) and loosely aggregated at the tip. *Carex lyngbyei*
is a similar species.

# Distribution

For current distribution, please consult the Plant Profile page for this
species on the PLANTS Web site. Slough sedge is a coastal plant growing
from San Luis County in California north through Oregon and Washington
to British Columbia. Slough sedge occurs at elevations below 900 m.

# Establishment 

*Adaptation*: Slough sedge is an obligate wetland species that prefers
fresh water. It grows in wet, shallow, inundated woods, meadows,
roadside ditches, coastal swamps, lakeshores, bogs, marshes, and
riverbanks. In muddy areas it can grow as a dense, single-species stand.
It often grows in association with skunk cabbage (*Lysichiton
americanum*). Slough sedge is very similar to Lyngbye\'s sedge in growth
form and appearance. Both species tolerate brackish often saline coastal
wetland areas; they often grow in similar habitats where saltwater and
freshwater meet, such as at the mouths of rivers entering the Pacific
Ocean, lagoons, or the Puget Sound.

###### *General*: *Carex obnupta* may be planted from bare root stock, seedlings from container stalk, or directly seeded into the soil. Bare root stock or seedlings are preferred revegetation methods, particularly in areas with moving water. Since slough sedge often grows in areas that are hydrologically quite dynamic, with both tidal and fluvial influences, bare root stock plantings are generally recommended. Seeds generally wash away in these conditions. Also, plants started from seeds tend to stay diminutive for over a year, with plant leaves remaining stunted and fragile for a considerable period of time.

*Live Plant Collections*: Live plant collections are appropriate only
under a very limited set of conditions. Loss of wetland ecosystems
exceeds 50% in most states and estuarine wetland losses have been as
high as 90%. Public lands that allow plant collections, require permits.
Permission from the landowner must be acquired to collect on private
lands. No more than 1/4 of the plants in an area should be collected; a
depth of 15 cm (6 in) is sufficiently deep enough for digging plugs.
This will leave enough plants and roots to grow back during the growing
season.

Live transplants should be planted as soon as possible. Plants should be
transported and stored in a cool location prior to planting. Plugs may
be split into smaller units, generally no smaller than 6 x 6 cm (2.4 x
2.4 in) with healthy rhizomes and tops. Weeds in the plugs should be
removed by hand. For ease in transport, soil may be washed gently from
roots. The roots should always remain moist or in water until planted.

Clip leaves and stem from 15 to 25 cm (6 to 10 inches); this allows the
plant to allocate more energy into root production and makes plants
easier to handle (the leaves can be sharp). Planting densities of
approximately 1 meter centers provide full coverage the first year
(given good site conditions). If there is flowing water, increase
planting densities to 1/2-meter centers. Plant densities should also be
increased with fine soils such as clay or silt, steep slopes or
prolonged inundation.

Ideally, plants should be planted in fall just after the first rains,
depending on the climate and geographic location. This enables plant
root systems to become established before heavy flooding and winter
dormancy occurs. Planting survival is highest when plants are dormant,
temperatures are cool, and soils are moist. Plants usually need to be
planted by hand, as soils are too moist to use machines.

In some areas, winter storms and high tides would wash away newly
transplanted seedlings. While in other areas, avoiding high tides and
high floods is recommended, because this combination will minimize plant
survival. Planting in the spring after high floods may be warranted in
this situation.

####### Seed Germination

-   Seeds usually have to be harvested by hand, as *Carex obnupta*
    Bailey grows in very wet habitats that are inaccessible by machine.
    *Carex obnupta* Bailey blooms from April to July. Collect seeds when
    they are ripe, from July to September. Make sure seed heads are
    full.

```{=html}
<!-- -->
```
-   Plant cleaned seeds in fall.

```{=html}
<!-- -->
```
-   Plant seeds in clean, weed free, moist seed bed.

```{=html}
<!-- -->
```
-   Broadcast seeds and roll in or rake 1/4\" to 1/2\" beneath the soil
    surface.

```{=html}
<!-- -->
```
-   Hold off watering so seeds doesn\'t float out.

```{=html}
<!-- -->
```
-   Some seeds may be lost due to scour or flooding.

```{=html}
<!-- -->
```
-   Use erosion control blankets to protect soil and seeds.

```{=html}
<!-- -->
```
-   Plants grown from seeds and planted from container stock have higher
    transplant survival than direct seeding.

```{=html}
<!-- -->
```
-   Recommended seed density is unknown at this time. Sedges tend to
    have low germination rates. While exact seeding prescriptions are
    unknown at this time, estimates of from 25% to 50% would be
    reasonable based on other *Carex* species.

```{=html}
<!-- -->
```
-   Nitrate fertilization greatly increases both biomass production and
    fecundity. Fertilizing plants at moderate nitrate levels increases
    flower stalk and seed production, seed weight, and seed viability.

-   Increasing temperatures from 21°C to 32°C increases germination
    percentages.

#### *Seed germination in greenhouse*

-   Clean seed - blow out light seeds.

-   Put in water with sphagnum moss.

-   Cold stratify seeds by putting in a cooler for 30 days to improve
    germination rates.

-   To grow seeds, plant in greenhouse in 1\" x 1\" x 2\" pots, 1/4\"
    under the soil surface. Keep moist at 100 ° F (plus or minus 5
    degrees). Sedges require high temperatures and constant moisture for
    successful germination. Seeds begin to germinate after two weeks in
    warm temperatures.

-   Plants are ready in 100 - 120 days to come out as plugs. These
    plants are very small; for planting, larger plugs in spring will
    improve revegetation success.

# Management

The leaves of slough sedge are cut in late summer (August) (Turner et
al. 1983). A knife was used to cut the plant at the base, as low to the
ground as possible. The best plants were said to be those growing in 10
cm (4\") of water. The cluster of leaves are cut off or pulled from the
tender white bases, where they break off at or just below the ground
level. Only the non-flowering, vegetative plants, called the \"female\"
plants, were gathered.

The harvested sedge leaves are bundled and taken home, where they are
sorted according to size; the longest ones, considered the best, were
put together and dried. After the leaves have dried slightly, they are
split exactly in half lengthwise, from bottom to top, using the
thumbnail. After being split, the leaves are dried completely and
bleached in the sun. They can then be bundled or stored.

*Traditional Resource Management*: Conservation practices include the
following: 1) gathering only during late summer after seeds are
produced; 2) gathering only infertile shoots without flowering stalks;
3) weeding out competing species and removing impediments to growth such
a stones and branches; 4) pruning shoots causes sedges to retranslocate
nutrients belowground, providing a nutrient reserve to stimulate new
growth the following growing season; 5) removal of long, dense shoots
provides good opportunities for seedling establishment and recruitment;
6) harvesting aboveground biomass maintains the sedge clone in juvenile
and mature life stages, removing decadent old portions of plants and
stimulating new growth; and 7) ownership of sedge beds provides the
basis for careful tending and sustainable yield of valued resources.

# Cultivars, Improved and Selected Materials (and area of origin)

CAOB3 is readily available through native plant nurseries and seed
companies within its range. Contact your local Natural Resources
Conservation Service (formerly Soil Conservation Service) office for
more information. Look in the phone book under "United States
Government." The Natural Resources Conservation Service will be listed
under the subheading "Department of Agriculture."

# References

Abrams, L. & R.S. Ferris 1960. *Illustrated flora of the Pacific
states*. 4 Vols. Stanford University Press, Palo Alto, California.

Baskin, C.C., E.W. Chester, & J.M. Baskin 1996. *Effect of flooding on
annual dormancy cycles in buried seed of two wetland Carex specie*s.
Wetlands 16(1): 84-88.

Baskin, J.M. & C.C. Baskin 1978. *Seasonal changes in the germination
response of Cyperus inflexus seeds to temperature and their ecological
significance*. Bot. Gaz. 139 (2): 231-235.

Baskin, J.M. and C.C. Baskin 1971. *Germination of Cyperus inflexus
seeds*. Bot. Gaz. 132(1):3-9.

Bernard, J.M. 1989. *Life history and reproduction in Carex*. Can. J.
Bot. 68:1441-1448.

Cooke, S.S. 1997. *A field guide to the common wetland plants of western
Washington and northwestern Oregon*. Seattle Audubon Society and
Washington Native Plant Society. 414 pp.

Gunther, E. 1945 rev. 1973. *Ethnobotany of western Washington*.
University of Washington Publications in Anthropology, 10(1). University
of Washington Press, Seattle, Washington

Grime, J.P., G. Mason, A.V. Curtis, J. Rodman, S.R. Band, M.A.G.
Mowforth, A.M. Neal & S. Shaw 1981. *A comparative study of germination
characteristics in a local flora*. Journal of Ecology 69:1017-1059.

Harper, J.L., J.T. Williams and G.R. Sagar 1964. *The behavior of soil
surfaces and its role in determining the establishment of plants from
seed*. Journal of Ecology 53:273-286.

Hickman, J.C. (ed.) 1993. *The Jepson manual. Higher plants of
Californi*a. University of California Press. 1399 pp.

Hoag, J.C. & M.E. Sellers 1995. *Use of greenhouse propagated wetland
plants versus live transplants to vegetate constructed or created
wetlands*. Interagency Riparian/Wetland Plant Development Project, USDA,
NRCS, Plant Materials Center, Aberdeen, Idaho.

Hoag, J.C. & M.E. Sellers 1994. *Seed and live transplant collection
procedures for 7 wetland plant species.* Interagency Riparian/Wetland
Plant Development Project, USDA, NRCS, Plant Materials Center, Aberdeen,
Idaho.

Keddy, P.A. & P. Constabel 1986*. Germination of ten shoreline plants in
relation to seed size, soil particle size and water level*: *an
experimental study*. Journal of Ecology 74:133-141.

Martin, A.C., H.S. Zim, & A.L. Nelson 1951. *American wildlife and
plants. A guide to wildlife food habits*. Dover Publications, Inc., New
York, New York. 500 pp.

Mason, H.L. 1957. *A flora of the marshes of California*. University of
California Press. Berkeley and Los Angeles, California. 878 pp.

Moser, C.L. 1993. *Native American basketry of southern California*.
Riverside Museum Press. 155 pp.

Stevens, M.L. 1999. *The effect of nitrogen fertilization on the growth,
reproduction, and nitrogen use efficiency of Carex barbarae.* Ph.D.
Dissertation, third paper. University of California, Davis, California.
In progress.

Schütz, W. 1998. *Seed dormancy cycles and germination phenologies in
sedges (Carex ) from various habitats*. Wetlands 18(2):288-297.

Thompson, K. & J.P. Grime 1983. *A comparative study of germination
responses to diurnally fluctuating temperatures*. Journal of applied
ecology 20:141-156.

Thompson, K. & J.P. Grime 1979. *Seasonal variation in the seed banks of
herbaceous species in ten contrasting habitats*. Journal of Ecology
67:893-921.

Turner, N.J., J. Thomas, B.F. Carlson, & R.T. Ogilvie 1983. *Ethnobotany
of the Nitinaht Indians of Vancouver Island*. Occasional Papers of the
British Columbia Provincial Museum No. 24. Province of British Columbia.
Ministry of Provincial Secretary and Government Service. Government of
Canada. Parks Canada Western Region.

Turner, N.J. 1982. *Ethnobotany of the Hesquiat Indians of Vancouver
Island*. Cultural Recovery Paper No. 2. British Columbia Provincial
Museum. Province of British Columbia. Ministry of Provincial Secretary
and Government Services.

Urbaniak, L. 1993. *Variability characteristics and comparison of Carex
arenaria L. and Carex ligerica* *Gray populations based on rhizome
characters*. Acta Societatis Botanicorum Poloniai. 63(1):77-81.

USDA, NRCS 1999. *The PLANTS database*. National Plant Data Center,
Baton Rouge, Louisiana. \<http://plants.usda.gov\>. Version: 990412.

# Prepared By

##### *Michelle Stevens*

Formerly USDA, NRCS, National Plant Data Center

*Chris Hoag*

USDA, NRCS, Idaho Plant Materials Center, Aberdeen, Idaho

# Species Coordinator

*M. Kat Anderson*

USDA, NRCS, National Plant Data Center

c/o Plant Science Department, University of California, Davis,
California

Edited: 19jun02 jsp; 29apr03 ahv; 31may06 jsp

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

*The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, sex, religion, age, disability, political beliefs, sexual
orientation, and marital or family status. (Not all prohibited bases
apply to all programs.) Persons with disabilities who require
alternative means for communication of program information (Braille,
large print, audiotape, etc.) should contact USDA\'s [TARGET
Center](http://www.usda.gov/oo/target.htm) at 202-720-2600 (voice and
TDD).*

*To file a complaint of discrimination write USDA, Director, Office of
Civil Rights, Room 326-W, Whitten Building, 14th and Independence
Avenue, SW, Washington, DC 20250-9410 or call 202-720-5964 (voice or
TDD). USDA is an equal opportunity provider and employer.*

*Read about [Civil Rights at the Natural Resources Convervation
Service](http://www.nrcs.usda.gov/about/civilrights/).*