little bluestem

not listed

N5 - Secure

SNR - Unranked

not listed

FACU - Facultative upland

FACU - Facultative upland

FACU - Facultative upland

Little bluestem is a very common, medium-height, warm season grass. It occurs in the United States, Canada, and Mexico east of the Rocky Mountains. It is found in dry open areas, including prairies, savannas, pastures, old fields, woodland openings, roadsides, and railroads. It grows under full sun in dry to moderately moist but well drained soil.

Little bluestem is highly variable. Plants in Minnesota are almost always mostly hairless. They rarely have hairs anywhere except on the basal leaves. In the early season, the basal leaves are usually blue.

Little bluestem is a perennial, cool season (C₃) grass that rises on basal leaves and a clump of multiple stems from a fibrous root system. There is sometimes a short, underground, horizontal stem (rhizome). In the spring it appears as a round, 2′ to 3′ (61 to 91 cm) high, loose or dense mound of narrow, bluish-green leaf blades. In mid-summer it produces flowering aerial stems (culms).

The stems (culms) are solid, erect, 1⁄32″to ⅛″ (1 to 3 mm) in diameter, and freely branched just near the top. They are usually 6″ to 36″ (15 to 90 cm) tall, sometimes taller. They may be round in cross section or slightly flattened. They are not grooved, and they do not root at the nodes. The nodes are swollen, and the culms are often wine red or purplish near the nodes. The base of the culm is erect, not laying on the ground and curving upward (decumbent). When young, the culms are light green or bluish green and are covered with a whitish, waxy bloom (glaucous). Later in the season they turn coppery, orangish, or reddish bronze. They remain erect throughout the winter.

Most of the leaves are basal. Stem leaves are alternate and are mostly on the lower part of the culm. The part of the leaf blade that surrounds the stem (sheath) is open, flattened, ridged (keeled) on the back, bluish green, and glaucous. The junction between the sheath and the leaf blade (collar) is pale and whitish. The leaf blade is distinctly narrowed before the collar, and the sheath is distinctly constricted near the collar. Where the leaf blade meets the sheath there is a thin, pliable appendage (ligule). The ligule is 1⁄64″to ⅛″ (0.5 to 2.5 mm) long and membranous. It has a fringe of short hairs at the top. The leaf blade is green, often glaucous, linear, 3½″ to 17¾″ (9 to 45 cm) long, and ⅛″ to ¼″ (3 to 7 mm) wide. It may be flat, folded, or curve upward along the margins. The midvein is noticeably thickened. Basal leaves may have scattered, long hairs, but stem leaves are almost always hairless.

The inflorescence is a single, spike-like, unbranched cluster (raceme). The racemes appear at the end of each of the several to numerous branches at the top of the culm, and also in the axils of the upper stem leaves. Each raceme is ¾″ to 3″ (2 to 8 cm) long, has 6 to 13 spikelets, and is on its own slender stalk that is up to ⅜″ (10 mm) long. It is tan or grayish-white, and it is usually zigzagged at maturity.

There is a pair of spikelets at each node of the raceme. One spikelet is stalkless, the other is stalked. The stalkless spikelet is ¼″ to 7⁄16″ (6 to 11 mm) long. It is usually fertile, containing both male and female reproductive parts (perfect), including 3 anthers. Glumes of a stalkless, perfect spikelet are 3⁄16″ to ⅜″ (5 to 10 mm) long, lance-shaped to linear, and membranous. The lemma is ¼″ to 9⁄16″ (7 to 9 mm) long, thin, membranous, and transparent. It has a ⅛″ to ⅝″ (2.5 to 17 mm) long awn at the tip. The base of this awn is bent and spirally twisted. The stalked spikelet is much shorter, 1⁄32″ to ¼″ (1 to 6 mm) long. It is usually sterile and has no lemma. Occasionally it is staminate and has a lemma. This lemma sometimes has an awn at the tip. This awn is straight and up to ⅛″ (4 mm) long.

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The description above refers to Schizachyrium scoparium var. scoparium, the only variety that occurs in Minnesota.

18″ to 36″

Dry to moderate moisture. Prairies, south-facing goat prairies, open woods, pine barrens, dunes, roadsides, railroads, old fields. Well-drained, rocky or sandy soil.

Early August to late September

Little bluestem is often used in prairie restorations.

Sources

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

Native

Common

Many subspecies, varieties, and forms of Schizachyrium scoparium have been described in the past. Most of them have been rejected and are now treated as synonyms. Currently, ITIS recognizes six varieties, GRIN recognizes four varieties, Flora of North America (FNA), USDA PLANTS, and NatureServe recognize three varieties, and Plants of the World Online and World Flora Online recognize no varieties. One variety has been raised to full species level by most sources as seaside bluestem (Schizachyrium littorale).

The “blue” in the name refers to the color of the emerging shoots in the early summer. The “little” in the name is a misnomer—this is not a little plant—but differentiates it from similarly-named big bluestem.

Habitat

Clump

Inflorescence

Infructescence

Winter

Location: Cass County