Festuca = a grass genus, + formis = like. The inflorescence is like that of a grass.
WCM Protologue Reference:
Nees ex Mast., J. Linn. Soc., Bot. 8: 248 (1865)
Vegetative parts: plants tufted (Culms often looking half-dead), 0.25–0.7 m tall, basal diameter 0.01–0.05 m, crown diameter 0.1–0.3 m, compact, without spreading rhizomes or stolons. Fertile culms sparingly branched, smooth or finely rugulose, green, 0.25–0.7 m tall, diameter at base 0.9–1.2 mm, diameter at apex 0.2–0.7 mm. Sheaths closely convoluted, 15–45 mm long, initially green, soon turning brown, apical margins narrowly membranous, hyaline shoulders membranous margins continuing behind awn, hyaline shoulder 0.01 of sheath body length, apex, excluding the membranous lobes, acute. Sheath-mucro penicellate, straight and erect, 7–25 mm long, awn more or less as long as the body of the sheath. Sterile branch leaf-sheath 1–1.5 mm long, hyaline shoulder 0.5 mm long, leaf-blade 10–15 mm long; leaf blade 0.3–0.5 mm wide. Males: male inflorescence with 21–50 spikelets or 50–100 spikelets or 101–500 spikelets, paniculate (obtriangular in shape), 25–80 mm long, 20–40 mm wide. Male inflorescence spathes persistent, like the floral bracts, chartaceous. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, linear or oblong, apex rounded, 8–13 mm, 2–3 mm, with 5–10 flowers, pedicels shorter than the spikelets, terete or angular. Male bracts more than twice as tall as flowers, 6–9 mm long, linear or ovate, acute, chartaceous, bract upper margin like body of bract, bract awn minute or absent, golden-brown. Male flower 2.2–2.4 mm long. Male tepals sepals more rigid than petals, chartaceous, petals membranous, oblong, inner and outer tepals the same length. Male outer lateral tepals conduplicate, glabrous. Anthers 2–2.3 mm long, exserted from the flowers. Pistillode present. Females: female inflorescence paniculate, 40–110 mm long, 10–25 mm wide, with 21–50 spikelets or 51–100 spikelets or 101–500 spikelets. Female spathes shorter than the spikelets, persistent, chartaceous. Female spikelet sessile or pedicel simple, oblong, apex rounded, 8–14 mm long, with 5–15 flowers, with 2–4 sterile bracts. Female bracts at least twice as long as flowers, 6–12 mm long, oblong, acute, chartaceous, apical margin like rest of bract, same as body of bract, awn minute or absent. Female flower 2–3 mm long, oblique, without a fleshy pedicel. Female tepals cartilaginous, glabrous and smooth, midrib flush with the tepal body, apices obtuse, inner and outer whorls the same length. Female outer lateral tepals conduplicate or keeled or winged, wings entire, narrower than body, 2–3 mm long. Female odd outer tepal oblong, 2–3 mm long. Female inner tepals oblong, 2–3 mm long. Staminodes present. Styles feathery, white, 3. Style bases free. Ovary with 1 locule, dehiscent. Fruit: seed (1.12–)1.31(–1.52) mm long, (0.52–)0.78(–1) mm in diameter, shape in side view elliptical, shape in diameter rectangular in cross section or triangular in cross section, tan, smooth.