Plants annual, forming tufts. Flowering stems erect,
sometimes from spreading bases, glabrous, darkened at the nodes. Leaf sheaths
rounded on the back to slightly keeled, glabrous, the ligule 0.5–3.0 mm long,
often somewhat torn or irregularly lobed or toothed. Leaf blades flat or with
inrolled margins, glabrous or more commonly roughened. Inflorescences open to
dense panicles with strongly ascending to spreading branches, erect. Spikelets
slightly flattened laterally, disarticulating above the glumes, with 1 perfect
floret and without additional staminate or sterile florets. Glumes rounded or
somewhat keeled, lanceolate, narrowed to a sharply pointed tip, awnless,
roughened on the midnerve, unequal in length, the lower glume shorter than the
floret, 1‑nerved, the upper glume slightly longer than the floret, 3‑nerved.
Lemma not membranous at maturity, lanceolate, sharply pointed at the tip,
rounded on the back, faintly 5‑nerved, roughened toward the tip, the base
with a tuft of very short, straight hairs, with a well‑developed awn 4–12
mm long (longer than the spikelet) attached just below the tip. Palea slightly
shorter than the lemma, membranous, 2‑nerved. Stamens 3. Fruits 1.2–1.6
mm long, narrowly oblong‑elliptic in outline, yellowish brown. Three or 4
species, Europe, Asia; introduced in North America.
Apera was included in the genus Agrostis by many earlier authors of
American floras (Steyermark, 1963), but it is distinct from that genus by
virtue of its spikelets with a well‑developed palea, a long‑awned,
relatively firm lemma, and unequal glumes (McNeill, 1981). These characters
appear occasionally in various species of Agrostis but are uncommon and
do not occur in tandem in that genus. Care must be taken not to confuse species
of Apera with the superficially similar Agrostis gigantea and A.
stolonifera.