Scirpus cyperinus

This native perennial plant consists of a clump of low vegetative shoots, from which arises one or more flowering stalks about 3-5' tall. The stout culms of the these flowering stalks are unbranched, bluntly 3-angled or terete (round in cross-section), medium green, and glabrous. Each culm has 5-9 alternate leaves along its length. The blades of these leaves are up to ½" (12 mm.) across and 2' long; they are ascending to widely spreading. Each blade is medium green, glabrous, and slightly indented along the middle of its length. The leaf sheaths are medium green, glabrous, and closed. The leaves of the low vegetative shoots are similar to the leaves of the flowering stalks, except the former are somewhat smaller than the latter and more evergreen. Each fertile culm terminates in a compound umbel of spikelets spanning about 4-6" long and wide. This compound umbel has many drooping branchlets that are slender, glabrous, and green. The outer branchlets terminate in small clusters of 3-12 sessile (or nearly sessile) spikelets. Each ovoid spikelet is about 5-6 mm. long and 3 mm. across; it becomes reddish brown and woolly at maturity, consisting of a dense head of perfect florets, scales, and bristles. Each floral scale is about 2 mm. long, lanceolate to ovate, and brown-membranous; each floret has a tripartite style, 3 stamens, and a developing ovary. At the base of the compound umbel, there are 3 or more large leafy bracts. Underneath each branched division of this umbel, there often occurs much smaller brown bractlets. The blooming period occurs from late summer to early fall. The florets are wind-pollinated. Each fertile floret is replaced by a tiny achene less than 1 mm. long. This achene is pale brown, 3-angled, and pointed at both ends; it is surrounded by 6 long bristles that are reddish brown, curly, and persistent. It is the exerted bristles of the many achenes in the spikelets that provide them with their woolly appearance. The root system is fibrous and short-rhizomatous. Wool Grass often forms colonies of plants.

The common name of this species is misleading because it isn't a member of the Grass family (Poaceae). Instead, it is a member of the Sedge family (Cyperaceae), like other Scirpus spp. To make matters even more confusing, these species are collectively referred to as 'Bulrushes,' even though they are not members of the Rush family (Juncaceae). Notwithstanding such problems with nomenclature, Wool Grass is one of the more attractive bulrushes, particularly during the early fall when its spikelets become woolly reddish brown. It can be distinguished from similar species by considering the following features

General: Sedge family (Cyperaceae). Woolgrass (Scirpus cyperinus) is a tall rhizomatous perennial with slender culms. This species is an erect grasslike plant up to 6.5 feet tall, commonly four to five feet (Tiner 1987). The leaves are smooth, flat, elongated, and up to ½ inch wide. The flowers occur in dense rounded clusters of greenish-brown spiklets arising from the top of the culm. The fruits are yellow-gray to white achenes surpassed by long red-brown bristles at maturity. The flowers are wind-pollinated and the achenes reach maturity in late summer. Achenes are small and light. An estimated average number of achenes per inflorescence is 108,000. The number of seeds (achenes) per pound has been estimated from 27 to 45 million. The reported numbers of chromosomes for woolgrass are 60, 64, or 70.

Distribution: Woolgrass ranges from New England and New York westward across Ohio to Iowa, and southward to North Carolina and Oklahoma. It is also found from Newfoundland to Minnesota south to Florida and Louisiana (Tiner 1987). For current distribution, please consult the Plant profile page for this species on the PLANTS Web site.

cotton grass bulrush, common wool-grass

Wool Grass is occasional to locally common throughout Illinois (see Distribution Map). It has been collected less often in the central section of the state. Habitats consist of both sandy and non-sandy wetlands, including marshes, swamps, sloughs (seasonal streams), sedge meadows, gravelly seeps, and borders of ponds. This species is somewhat variable across its range.

Scirpus cyperinus var. pelius Fernald:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Scirpus cyperinus (L.) Kunth:
Canada (North America)
Mexico (Mesoamerica)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que.; Ala., Ark., Calif., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis., Wyo.; Mexico.

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Newfoundland to British Columbia, south to Florida and Texas, with disjunct populations in the Black Hills of South Dakota and Wyoming (Crook County) and the Yellowstone Plateau (Park County).

Woolgrass is found in irregularly flooded tidal fresh marshes, inland marshes, wet meadows, and swamps. This species grows best in areas with wet soil moisture content and is seldom found in more than a few inches of water (Voss 1972). It prefers peat or sandy soil types in full to partially sunny locations. Woolgrass is an early successional species. It often invades disturbed wetlands where the soil has been exposed by drawdown. It tolerates a wide range of hydrologic, soil and chemical conditions. It has been found in peat soils with pH levels as low as 3.7 and high as 8.4. Woolgrass performs well in created and constructed wetlands for the treatment of acid mine drainage if the pH of the influent mine drainage is > 4. Woolgrass has been found growing in title rice fields where the salinity was 9000 mg/L.

Though woolgrass will grow in water it is seldom found growing in water more than a few inches deep. Mature woolgrass plants form raised tussocks, which tolerate greater water depths than seedlings.

Woolgrass clonal clumps collected from an acid mine drainage contaminated wetland were compare with clumps from an uncontaminated wetland. Plants from the contaminated source population had more total root length, more tillers, larger clump diameter and greater biomass than plants from the uncontaminated source population when grown in the presence or acid mine drainage. Plants from the two populations were not different for growth characteristics when grown in the presence of tap water. Variation for growth characteristics among individual clones in the presence of acid mine drainage suggests a potential for genotypic selection in woolgrass for increased growth in presence of acid mine drainage.

Plants aggregated in dense tussocks; rhizomes branching, short, tough, fibrous. Culms: fertile ones upright or nearly so; nodes without axillary bulblets. Leaves 5–10 per culm; sheaths of proximal leaves green to red-brown; proximal sheaths and blades with septa few to many, conspiucuous or inconspicuous; blades 22–80 cm × 3–10 mm. Inflorescences terminal; rays ascending or sometimes spreading, scabrous throughout or main branches smooth proximally, rays without axillary bulblets; bases of involucral bracts reddish brown, brownish, or blackish, not glutinous. Spikelets in dense cymes of 2–15, central spikelet of each cyme sessile, others sessile or pedicellate, spikelets broadly ovoid, ovoid, or sometimes cylindric, 3.5–8 × 2.5–3.5 mm; scales reddish brown, brownish, or blackish, ovate or narrowly ovate to oblong-ovate or oblong-elliptic, 1.1–2.2 mm, apex apiculate or short-mucronate, apiculus or mucro to 0.1 mm. Flowers: perianth bristles persistent, 6, slender, contorted, much longer than achene, smooth, projecting beyond scales, mature inflorescence appearing woolly; styles 3-fid. Achenes whitish to very pale brown, elliptic or obovate in outline, plumply trigonous or plano-convex, 0.6–0.9 × 0.3–0.5 mm. 2n = 66.

The numerous spikes, in an open inflorescence subtended by several leaf-like bracts, and the elongate flower bristles separate this species from other SCIRPUS in our area.

Eriophorum cyperinum Linnaeus, Sp. Pl. ed. 2, 1: 77. 1762; Scirpus cyperinus var. andrewsii (Fernald) Fernald; S. cyperinus var. pelius Fernald; S. rubricosus Fernald

Wool Grass is occasional to locally common throughout Illinois (see Distribution Map). It has been collected less often in the central section of the state. Habitats consist of both sandy and non-sandy wetlands, including marshes, swamps, sloughs (seasonal streams), sedge meadows, gravelly seeps, and borders of ponds. This species is somewhat variable across its range.

Marshes, moist meadows, ditches, shallow ponds, frequently growing in disturbed areas; 0–800m.

Propagation by Seed: Woolgrass seeds should be sown in a cold frame as soon as they are ripe in a pot standing in three centimeters of water. The seeds should be just covered with soil. Soil should be constantly damp until germination is complete. The seeds germinate quickly. When they are large enough to handle, plant them into their permanent positions in early summer.

A review of woolgrass seed germination studies suggest that woolgrass seed is initially dormant and cold-most stratification followed by divergent day/night temperatures (90/77 ºF) increase germination percentage. Light appears necessary for germination of woolgrass seed. Woolgrass seed, unlike seed of many aquatic species is apparently not injured by drying. But, dry storage of woolgrass seed decreases germination percentage. Seed can be stored submerged in distilled water for extended periods. Woolgrass exhibited at least 50 % germination after submerged storage at 37-39 ºF for 35 months.

Propagation by Stem Division: Divisions should contain both shoots and rhizomes. Large divisions can be planted directly into their permanent positions. It is best to pot smaller divisions and grow them in a cold frame, out-planting when they are well established in the summer.

Several leaf beetles (Donacia spp. & Plateumaris spp.) feed on the foliage of Scirpus spp. (Bulrushes), while the seed bugs Cymus luridus, Cymus angustatus, and Cymus discors feed on the seedheads. The latter two seed bugs have been observed on Wool Grass specifically. The caterpillars of Euphyes dion (Dion Skipper) and the moth Ledaea perditalis (Lost Owlet) also feed on Wool Grass. Bulrushes are an important source of food and cover to many vertebrate animals. Many species of ducks and other wetland birds feed on the seedheads of bulrushes; Canada Geese and the Trumpeter Swan also eat the foliage. See the Bird Table for a listing of these species. Because Wool Grass and other bulrushes often form dense colonies of plants, they provide good nesting habitat for various species of wetland birds. Muskrats eat both the foliage and rhizomes of bulrushes, while the Meadow Vole eats the seedheads.

Fruiting late summer–early fall (Aug–Sep, earlier in s United States).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 5
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Please consult the Plants Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status and wetland indicator values.

Muckalee Germplasm wool-grass was released as source identified material by the Jimmy Carter Plant Materials Center (GA) in 2008. It can be used in small constructed wetlands, wetland restoration and riparian buffers. Available through wetland plant nurseries. Contact your local Natural Resources 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.”

An ecologist suggested that a woolgrass community in Wisconsin developed with the water-level control program. Water levels were drawn down, and woolgrass seedlings established on the exposed mudflats. Seedling density was highest on the driest portion of the formally submerged area. Once established, woolgrass survived in this area after re-flooding.

Woolgrass propagules should be planted in saturated, but not inundated soil. Seedlings will not survive prolonged inundation at the time of installation. During the first growing season following planting, water depths should be kept at or near the soil surface as much of the time as possible. But, standing water during periods when plants are dormant such as winter and early spring is not as harmful. Once plants have formed tussocks they can tolerate greater water depths for longer periods. Tussocks formation takes several years from seedlings and a year longer from seed. Water levels are critical though out this period.

Newly established woolgrass meadows should be burned each year usually in the spring for the first three or four years; then once every two or three years. Historically, dense woolgrass stands are best maintained by mowing or prescribed burning.

Researchers studied primary succession in a created freshwater wetland by comparing plant cover, species density and biomass in the created wetland with that in a reference wetland. Woolgrass and cypress panicgrass (Dichanthelium dichotomum var. dichotomum) were the dominate species in the reference wetland. In contrast, blunt spikerush (Eleocharis obtusa) and tapertip rush (Juncus acuminatus) were the dominate species in the created wetland.

A slow plant decomposition rate in wetlands subjected to acid mine drainage may result is a low level of nutrient cycling because a substantial proportion of nutrients remain unavailable in the organic matter. Two studies indicate that the decomposition rate of woolgrass and common rush (Juncus effusus) were significantly lower that of calamus (Acorus calamus) and rice cutgrass (Leersia oryzoides), when subjected to acid mine drainage.

The preference is full or partial sun, wet to moist conditions, and soil that is muddy, sandy, or gravelly. Shallow water is tolerated. The easiest way to start new plants is by division of the vegetative shoots.

Ethnobotanic: Woolgrass stems were woven to make matting and ropes. The fruiting tops of the plant were used as a resilient material for stuffing and making pillows (Moerman 1998). The small rushes were used in making woven mats and storage bags (Ibid.).

Wildlife: Woolgrass is one of several wetland species that are important in providing food, cover and nesting material for waterfowl and other wildlife. Woolgrass acts as a buffer against wind and wave action, which permits other aquatic species to grow in otherwise unfavorable environments. Muskrats eat both the foliage and rhizomes of woolgrass. Voles eat the seedheads.

Phytoremediation: Woolgrass is a prevalent species in natural acid mine drainage wetlands in West Virginal and Pennsylvania. Woolgrass is useful in constructed wetlands for ammonium removal and the treatment of municipal wastewater and ash pond seepage. Woolgrass was difficult to establish in a peat-sand filter bed that was irrigated with sewage effluent in Minnesota. The researchers concluded that woolgrass required a wetter environment.