3. Calamagrostis stricta (Timm.) Koeler ssp. inexpansa (A. Gray) C.W. Greene (northern reedgrass)

Pl. 133 e–g; Map 541

C. stricta var. brevior Vasey

C. inexpansa A. Gray

C. inexpansa var. brevior (Vasey) Stebbins

Plants forming clumps or colonies. Flowering stems 30–60(–100) cm long. Leaf sheaths glabrous or less commonly somewhat roughened, the ligule 1–4 mm long. Leaf blades 4–35 cm long, 1–5 mm wide, the margins usually strongly inrolled, usually not glaucous. Inflorescences 5–18 cm long, dense, narrow, and spikelike, the branches erect or strongly ascending, even at fruiting, mostly less than 3 cm long. Glumes 2.5–5.5 mm long, elliptic‑lanceolate to narrowly ovate, tapered to a sharp point at the tip, glabrous or roughened. Floret with the basal tuft of hairs mostly about as long as the lemma. Lemma 1.5–3.5 mm long, narrowly ovate, the awn attached near the midpoint of the midnerve, straight or nearly so, sometimes difficult to distinguish from the basal hairs. 2n=28, 42, 56, 58, 70, 84, 85, 88, 89, 92, 98, 102, 103, 105, 126. June–August.

Uncommon in southern Missouri north to Jackson County (northern U.S. south to West Virginia, Missouri, and California; Canada, Alaska, Asia). Banks of rivers, margins of sinkhole ponds, and sandy margins of bottomland forests; also roadsides and ditches.

This species is morphologically similar to C. canadensis, and some specimens can be difficult to determine between the two species. As in C. canadensis, some populations reproduce apomictically (Nygren, 1954). It is treated here in the sense of Greene (1980, 1984), who recognized two subspecies within C. stricta. Subspecies stricta differs from ssp. inexpansa in its lemmas with shorter basal hairs, thinner glumes, and mostly lower chromosome numbers. It appears to reproduce all or mostly sexually.