Plants with culm bases thickened, contiguous; rhizomes of attached culm bases, knotty, stout, covered with dark fibers and chaff from old leaf bases. Leaves: leaf sheaths distally with at least some hairs; blades with margins distantly to closely scabrid, surfaces glabrous or densely hirtellous. Fertile scales totally or distally puberulent.

Fruiting late spring-summer. Moist clays to sands or sandy peats, in prairies, savannas, glades, pinelands, acidic to basic sites; 0-1000 m; Ont.; Ala., Ark., Del., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Mich., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., S.C., Tenn., Tex., Utah, Va.

Perennial herb with rhizomes, loosely tufted or culms sometimes solitary to 1 m tall

Leaves: basal, ascending, shorter than or as long as culms, 1 - 2 mm wide, narrowly linear, parallel-veined, marginally rolled inward above, sometimes hairy, with a sheathing base that encloses the stem. Sheaths shorter than the blade, broadly margined, slightly hairy above, opening at the top.

Inflorescence: a terminal, simple or compound, dense or widely spreading anthela of spikelets subtended by leaf-like bracts (an anthela is a type of inflorescence which bears lateral branches that are longer than the main axis). Bracts shorter than or surpassing the inflorescence.

Flowers: minute, subtended by a floral scale, lacking sepals and petals. Stamens three, exserted. Anthers 2 - 2.5 mm long. Pistil one. Style enlarged basally, fringed, two-cleft.

Fruit: a one-seeded achene, yellowish to brown, to 1 mm long, swollen, reverse egg-shaped and biconvex, minutely cell-like and wrinkled in vertical rows. Seed with a thin, non-adherent wall.

Culm: sometimes solitary, to 1 m long, slender, thickened basally, circular or broadly oval in cross-section, angled above, solid, variably hairy, growing above the leaves.

Spikelets: reddish brown, 0.5 - 1 cm long, widely egg-shaped to cylindrically lance-shaped. Floral scales spirally arranged and overlapping, 2.5 - 3.5 mm long, widely egg-shaped or reverse egg-shaped, minutely hairy, with a midrib that extends past the apex into a tiny point. Lower spikelet scales non-flowering, larger than the fertile flower scales, and often bladed.

Similar species: The similar Fimbristylis autumnalis differs by having three-cleft styles and three-angled achenes.

Flowering: July to early August

Habitat and ecology: Most common in flat sandy grasslands near Lake Michigan. It also has been found in a sandy wet prairie and in other sandy areas away from the lake.

Occurence in the Chicago region: native

Etymology: Fimbristylis comes from fimbria, meaning "a fringe," and stylus, meaning style, referring to the hairy-fringed style in the genuine species. Puberula means tiny-haired.

Author: The Morton Arboretum

In moist, sandy soil in an interdunal flat habitat. It must be very local since I have seen it only three times.