5. Agrostis perennans (Walter) Tuck. (upland bent, autumn bent grass)
Pl. 130 a,
b; Map 527
A. perennans var. aestivalis Vasey
A. clavata Trin.
Plants perennial, with rhizomes absent or very short,
forming tufts or clumps. Flowering stems 15–90 cm long, erect to spreading, often
ascending from spreading bases. Leaf sheaths glabrous, the ligule 0.7–4.0 mm
long. Leaf blades 3–20 cm long, (2–)3–8 mm wide, flat, glabrous or somewhat
roughened, bluish green. Inflorescences 8–25 cm long, open panicles, erect or
somewhat nodding, the main branches loosely ascending to spreading, slender,
branched again mostly at or below the middle (sometimes slightly above the
middle), usually somewhat roughened. Glumes 1.6–2.8 mm long. Lemma 1.2–2.3 mm
long, narrowed to the slender tip, sharply pointed or truncate at the very tip,
usually somewhat roughened, awnless or with a slender straight awn attached
below the middle, this 0.5–2.0 mm long, shorter than the spikelet. Palea absent
or much less than 1/2 as long as the lemma, nerveless. Stamens 3, the anthers
0.3–0.6 mm long. Fruits 1.0–1.4 mm long, yellowish brown to olive brown. 2n=42.
Scattered to common nearly throughout Missouri (eastern U.S. west to North Dakota and Texas; Canada, Mexico). Mesic upland forests, bottomland forests,
margins of ponds and sinkhole ponds, banks of streams and rivers, fens, shaded
ledges and crevices of bluffs, and less commonly upland prairies; also
roadsides, railroads, pastures, paths, and lawns.
Some botanists (Steyermark, 1963) separate plants with more
leaves, slightly longer pedicels, and smaller spikelets as var. aestivalis.
However, there is nearly total morphological overlap between the two varieties
for all of these characters. Plants attributed to var. aestivalis
usually occur in densely shaded habitats, and it may be that their appearance
is environmentally induced.