75. Festuca L. (fescue)
Plants perennial, sometimes with rhizomes, forming tufts,
clumps, or loose colonies. Flowering stems erect or ascending, sometimes from
spreading bases, glabrous. Leaf sheaths open nearly to the base (closed nearly
to the tip in F. rubra), the ligule relatively short, truncate or
slightly concave. Leaf blades flat, folded, or with inrolled margins, with
flat, sharply pointed tips. Inflorescences open or narrow panicles with
ascending to spreading or downwardly angled branches, these sometimes arched or
curved, the spikelets single or in small clusters toward the branch tips, but
not regularly paired, all similar in size and appearance and with fertile
florets (rarely some of the florets replaced with vegetative bulblets in F.
arundinacea). Spikelets elliptic‑lanceolate to ovate in outline,
somewhat flattened, with 3–10 florets. Glumes shorter than the rest of the
spikelet, pointed at the tip, awnless, glabrous or rarely roughened or hairy,
the lower glume shorter, 1‑nerved, the upper glume 3‑ or 5‑nerved.
Lemmas sharply pointed or less commonly bluntly pointed to rounded at the tip,
often awned, rounded on the back, faintly to strongly 3‑ or 5‑nerved
with the nerves converging (arched inward) toward the tip, glabrous (hairy in
some forms of F. rubra). Paleas as long as or slightly longer than the
lemmas, narrowly elliptic. Stamens 3, the anthers yellow. Ovaries sometimes
hairy at the tip. Fruits oblong‑elliptic in outline, nearly circular in
cross‑section, with a narrow groove along 1 side. About 450 species,
worldwide, especially in temperate regions.
Generic limits among Festuca and its relatives remain
controversial. Most botanists accept the separation of the annual fescues into
the genus Vulpia, although a few non‑Missouri species are
intermediate between the two groups for some characters. A more difficult
problem is the relationship between Festuca and Lolium.
Traditionally, these have been easily separable because of the spicate
inflorescence and single glume of Lolium, as opposed to the paniculate
inflorescence and pair of glumes in Festuca. Recent studies involving a
number of independent lines of evidence, including hybridization experiments,
cytogenetic details, examination of leaf anatomy, seed protein analysis, and
investigation of chloroplast DNA restriction site variation (reviewed by
Darbyshire, 1993) have shown that the traditionally classified Festuca
subgenus Schedonorus (P. Beauv.) Peterm. (represented in the Missouri flora by the widespread, introduced F. arundinacea and F. pratensis)
is more closely related to Lolium than to Festuca subgenus Festuca
(which includes the rest of the Missouri species of perennial fescues).
Darbyshire (1993) concluded that subgenus Schedonorus should be
transferred to Lolium and published the necessary new combinations under
that genus. However, questions remain about the appropriate level at which to
recognize these groups (Aiken et al., 1997). It may prove more acceptable to
combine all of them into a single, broadly defined, genus or to recognize all
three as distinct genera, once other subgenera of Festuca have been
studied in more detail. Thus, it seems most expedient to retain the traditional
classification of Festuca (to include subgenus Schedonorus) for
now, with the caveat that future studies may require large‑scale changes
in the generic delimitation of Festuca.