Carex Obnupta - Slough Sedge

Family: Cyperaceae (Sedge family) [E-flora]

Identification

Synonyms

General: Perennial, densely tufted herb from long, creeping rhizomes and fibrous roots, the roots with soft, reddish-brown hairs; stems 30-150 cm tall, arising a few or many together, longer than the leaves. [IFBC-E-flora]
Leaves: Sheaths tight, cross-wrinkled, reddish- to brownish-tinged at the base, the lowest ones breaking into threads; ligules as long as wide, rounded; blades 2 to 5 per stem, flat to channeled, borne on the lower 1/4 of the stem, 3-10 mm wide, the lower ones reduced.[IFBC-E-flora]
Flowers: Spikes 3 to 7, the terminal 2 (sometimes 1 or 3) linear, 1.5-6 cm long, long-stalked, with many male flowers, the lower spikes 2 to 4, cylindrical, 1.5-6 cm long, with female flowers, or some with male flowers above the female flowers, these short-stalked, spreading or nodding; bract subtending the lowest spike leaflike, sheathless, longer than the inflorescence, the bracts reduced above. [IFBC-E-flora]
Fruits: Perigynia broadly egg-shaped, leathery, 2.2-3.5 mm long, 1-1.2 mm wide, greenish or brownish, biconvex, smooth, faintly nerved, marginally 2-ribbed, the bases round, short-stalked, beakless or short-beaked, the beaks 0.1-0.2 mm long, entire or nearly so; female scales lanceolate, long-pointed or awned, as wide as and much longer than the perigynia, reddish-brown to dark brown, with 3-nerved, lighter centres, with narrow, translucent margins; stigmas 2; achenes lens-shaped, sometimes constricted in the middle, smooth, 1.6-2.2 mm long. [IFBC-E-flora]
USDA Flower Colour: Yellow
USDA Blooming Period: Mid-Spring
USDA Fruit/Seed characteristics:

Colour: Brown
Present from Spring to Summer [USDA-E-flora]

Habitat / Range

Origin Status: Native [E-flora]


Ecological Indicator Information
A shade-tolerant/intolerant, submontane to montane, Pacific North American sedge. Occurs in hypermaritime to submaritime cool mesothermal climates on wet to very wet, nitrogen-rich soils (Moder and Mull humus forms); its occurrence decreases with increasing elevation and continentality. Scattered to plentiful (often dominant) in graminoid-dominated, semi-terrestrial communities; on water-collecting sites (fens, bogs, and marshes) with gleysolic or organic soils. A nitrophytic species characteristic of nutrient-rich wetlands. [IPCBC][E-flora]


Other Uses


Cultivation

"Another harvesting technique was the intentional thinning of density-dependent species such as slough sedge (Carex obnupta) for basketry; this is said to aid the growth and reproduction of the plants (Craig 1998). Similar thinning has been observed to enhance the growth of Indian hemp (Apocynum cannabinum), cattail and stinging nettle; all of these die back in the winter, and hence are not harmed by late-season harvesting." [FCTM USDA]


References


Page last modified on Sunday, February 3, 2019 10:28 AM