rough bentgrass

not listed

N5 - Secure

S3 - Vulnerable (see below)

In 1984 Agrostis geminata, considered by some Agrostis scabra var. geminata, one of several described varieties of this species, was listed as Special Concern in Minnesota due to its limited habitat type. It was delisted in 2007 because the varieties of A. scabra are no longer recognized and the species as a whole is considered stable. NatureServe has not yet updated its conservation status for the state.

FAC - Facultative

FAC - Facultative

FAC - Facultative

Rough bentgrass, also called ticklegrass, is a widespread and very common grass. It is native to eastern Asia and North America. In North America it has been recorded in every state and province except Oklahoma, but it is uncommon to rare in the southeast and in the lower Midwest United States, and uncommon in the Canadian high arctic. It is very common in Minnesota. It is found in a wide variety of habitats and grows in a wide range of conditions. It is found in open woodlands and forest openings; in prairies, shrublands, and meadows; in swamps, bogs, and marshes; on stream and lake margins; and on roadsides, in ditches, and in other disturbed areas. It grows under full sun, but it is tolerant of shade. It grows in soil that is moist, moderately moist, or dry, that may be sandy, gravelly, or loamy. It is a pioneer species, one of the first to invade recently disturbed areas, including abandoned fields and forest clearcuts. It flowers from June to September depending on location and it sheds its seeds in late summer. At a distance a group of mature tufts looks like a purple haze.

Rough bentgrass is a perennial, cool season (C₃) grass that rises on basal leaves and a clump of multiple stems from a fibrous root system. It does not form underground horizontal stems (rhizomes) or produce above-ground runners (stolons).

The stems (culms) are hairless, round in cross section, unbranched, and 6″ to 36″ (15 to 90 cm) tall. They may be erect or curve upward from the base (ascending). There are usually 1 to 3 areas (nodes) below the middle of the stem from which the leaves emerge. The nodes are slightly swollen, dark, and hairless. Between the nodes the stem is hollow.

Most of the leaves are basal. Basal leaves are linear, 1½″ to 5½″ (4 to 14 cm) long, 1⁄32″ to ⅛″ (1 to 3 mm) wide. The upper surface is slightly rough to the touch and the margins are rolled inward toward the upper side. Basal leaves are usually present at flowering time. Stem leaves are similar, but the blade is shorter and flat. The base of the leaf that wraps around the stem (sheath) is open, hairless, and usually smooth, sometimes minutely roughened. The collar is not strongly developed. It does not have developed shoulders, ear-like projections (auricles), or hairs on the sides. The ligule is membranous, translucent, 1⁄16″ to 3⁄16″ (2 to 5 mm) long, and irregularly torn at the tip.

The inflorescence is a branched arrangement (panicle) at the end of each flowering stem. The panicle is diffuse, reddish-purple, broadly egg-shaped in outline, 3″ to 10″ (8 to 25 cm) long, rarely longer, and 3⁄16″ to 8″ (0.5 to 20 cm) wide, often as wide as long. At maturity the panicle often detaches as a unit at the base, forming a tumbleweed. The lowest node has 2 to 7 branches. Lower branches are 1½″ to 4¾″ (4 to 12 cm) long. The branches are widely spreading to ascending, sometimes drooping, flexible, rough to the touch, and branched again above the middle. The spikelets are well spaced, not crowded, at the ends of the branchlets.

The spikelets are lance-shaped and greenish-purple at first, often purple at maturity. Each spikelet has a lower and an upper sterile bract (glume) at the base and a single floret. The glumes are lance-shaped, keeled, and rough, at least toward the tip. The lower glume is 1⁄16″to ⅛″ (1.8 to 3.4 mm) long. Subtending the floret there is and outer bract (lemma) and an inner bract (palea). The lemma is 1⁄32″ to 1 ⁄16″ (1.4 to 2.0 mm) long and narrowed to a slender point at the tip. Five prominent veins are visible on the outer surface. There may be a 1⁄128″ to ⅛″ (0.2 to 3.0 mm) long bristle-like extension of the midvein (awn) at the tip. Sometimes there is no awn. The palea is minute, up to 1⁄128″ (0.2 mm) long, or is sometimes absent. There are three stamens. The anthers are 1⁄64″ to 1 ⁄32″ (0.4 to 0.8 mm) long.

6″ to 36″ (15 to 90 cm)

Moist, moderately moist, or dry. Open woodlands, forest openings, prairies, shrublands, meadows, swamps, bogs, marshes, stream sides, lake margins, roadsides, ditches, and other disturbed areas. Full sun. Sandy, gravelly, or loamy soil.

June to September

Sources

2, 3, 4, 5, 7, 24, 28, 29, 30.

Native

Very common

Location: Weaver Dunes Preserve, Cox Unit