Flower:

Branching cluster (panicle) 4 to 8 inches long at the top of the stem, sometimes erect but typically nodding, the main branches ascending to arching, with 1 or 2 spikelets (flower clusters) per branch. The base of the panicle is often partially hidden in the uppermost sheath. Spikelets are short to long-stalked, single-flowered, 15 to 35 mm (~½ to 1 1/3 inch) long, narrowly lance-elliptic in outline.

At the base of a spikelet is a pair of bracts (glumes), both similar, thin, hairless, 5-veined, 15 to 35 mm long, the lower glume slightly longer than the upper glume but both longer than the floret, narrowly lance-shaped with a long taper to a pointed tip that extends to an awn up to 7 mm long. Florets are surrounded by a pair of bracts (lemma and palea), the lemma thicker than the glumes, 5-veined, 7 to 13 mm long, hairy, narrowly lance-linear with a stiff awn 4 to 8 inches long covered in short, stiff hairs; the palea is about as long as the lemma and similarly hairy. The thickened base of the floret (callus) is covered in straight, light brown hairs.

Leaves and stems:

Leaves are basal and alternate on the lower stem, .5 to 4 mm (to 1/6 inch) wide, basal leaves up to 16 inches long, stem leaves to 12 inches long, hairless on the lower surface, usually rough and minutely hairy on the upper surface, the edges often rolled in (involute). Sheaths on lower stem leaves may be minutely hairy on the surface. The ligule (membrane where the leaf joins the sheath) is up to 7 mm (~¼ inch) long and usually jagged across the top edge. Nodes are mostly smooth, or the lower nodes with a few hairs; lower nodes are usually hidden by the sheaths. Stems are mostly smooth except at the nodes.

Fruit:

At maturity, glumes turn pale and florets straw-colored to light brown, the florets shedding individually leaving the glumes behind on the stalk. The floret base has a needle-like point and the stiff hairs on the surface cause it to attach to anything unlucky enough to pass by. The long awn twists in response to changes in moisture, coiling and uncoiling as it dries, usually loosely curled above the spirally twisted base, and eventually drills into the ground. Grains (seeds) are light brown, linear, 2 to 4 mm long.

Notes:

Needle-and-thread Grass is a common grass of the Great Plains and reaches the eastern edge of its native range in Minnesota; it's considered introduced farther east. There are 2 Hesperostipa (formerly Stipa) species in Minnesota; Hesperostipa spartea (Porcupine grass) is generally a larger plant, with spikelets up to twice the size of H. comata and its awn more stout and usually bent once or twice rather than curling.

There are 2 recognized subspecies of H. comata: subsp. intermedia has generally straight awns 2½ to 5 inches long, the lower nodes are all exposed, the panicle is fully extended out of the upper sheath, and prefers open pine woods; subsp. comata has curling awns 3 to 8+ inches long, the lower stem nodes are usually hidden by the sheaths, the panicle is often partially enclosed by the upper sheath, and is the more common of the two, prefering open grasslands and is found in Minnesota.