| # Festuca of North America |

S.G. Aiken, M.J. Dallwitz, C.L. McJannet, and L.L. Consaul

### Festuca arundinacea Schreb.

TALL FESCUE, REED FESCUE.

Spicil. Fl. Lips.: 57. 1771. F. elatior var. arundinacea (Schreb.) Wimmer, Fl. Schles. ed. 3: 59. 1857. F. elatior subsp. arundinacea (Schreb.) Celak., Prodr. Fl. Bohm 1: 51. 1867. Lolium arundinaceum (Schreb.) Darbysh., Novon 3: 241. 1993. Type: Scheuchzer, Agrostaphia, tab. V, fig. 18, 1719. Lectotype selected Reveal et al. (1991), Taxon 40: 136.

Festuca elatior L. Sp. Pl.: 75. 1753, nom. rejic. Type: Herb. Linn. no. 92.17. LINN Lectotype: Linder, Bothalia 16: 59. 1986. More extensive synonymy in the Catalogue of New World Grasses. R.J. Soreng, Project Leader, US.

Habit. Plants deep green, (30–)50–150(–200) cm high (Markgraf-Dannenberg 1980), densely tufted, tiller bases stiffly erect or not stiffly erect, bases not purplish, horizontal rooting stems present or absent (rhizomes short, if present). Vegetative shoots arising outside, or breaking through the base of existing sheaths.

Vegetative morphology. Sheaths glabrous or glabrescent or with trichomes (occasionally lower sheaths glabrous, upper sheaths scabrous), not conspicuous at the base of the plant or conspicuous at the base of the plant, persisting for more than 1 year, splitting between the veins ("only tardily" Gleason and Cronquist 1991) or remaining entire, not conspicuously splitting between the veins (usually pale straw coloured), open more than half their length. Collars glabrous. Auricles present, claw-like. Auricular cilia present, long and pilose-like. Ligules 0.4–1 mm long, ciliate. Leaf blades 11–30 cm long, erect, stiffish. Adaxial blade surfaces glabrous or with trichomes (veins prominently ridged), abaxial blade surfaces glabrous. Leaf blades flat, 4–12 mm wide (coarse, thick and predominantly vein-ridged on upper surface). Veins 15–25. Adaxial to abaxial sclerenchyma strands present. Uppermost culm leaf sheaths not inflated. Flag leaf blades 8–20(–25) cm long. Culm nodes becoming exposed, 1–2 (when visible); internodes glabrous.

Floral morphology. Inflorescence paniculate, 10–35 cm long. Inflorescence branches at the lowest node 2–3 (rarely 1, the shortest branch having few to several spikelets), spreading, 6–12 cm long (lax, subsp. arundinacea). Rachis angular in cross section, trichomes mainly on the ridges. Spikelets aggregated towards the ends of the branches; 5–15 on the longest branches; (5–)8–15.5 mm long (10–12 mm subsp. arundinacea), 2–3.5 mm wide. Proliferating spikelets absent (one specimen from Arizona, NAU 37218, illustrated in the image library). Florets 3–6(–9). Glumes unequal (lanceolate, subsp. arundinacea), glabrous (or almost so, sometimes with a few sparse trichomes on the main vein), margins not ciliate. First glume 3–6 mm long, veins 1–3. Second glume shorter than the first lemma, (4–)4.5–7(–9) mm long, veins 3(–5). Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma (4–)7–9(–11.5) mm long, with 5 distinct veins in dorsal view or nerveless in dorsal view or sometimes with only the centre vein distinct, glabrous or with trichomes, trichomes over the entire surface (usually, with scabrous trichomes mainly on the veins); apex entire or apically cleft (subsp. arundinacea). Lemma awn 0–1.5(–4) mm long (unawned subsp. arundinacea). Palea 6.7–10.3 mm long, glabrous between the keels. Lodicules with marginal teeth, glabrous, 0.9–1.6 mm long. Anthers (2.5–)3–4 mm long. Ovary apex glabrous. Caryopsis 2–3 mm long.

Cytology. 2n = 28, or 42, or 56, or 63, or 70.

Habitat and distribution. Introduced; cultivated crop; meadows. Widely planted for hay, often forming coarse tussock-like clumps along roadsides and irrigation ditches. We have not seen records from Ala, Conn, Fla, Mass, Maine, Ohio, RI, Va., or Vt but strongly suspect this species has been planted in most if not all of these states. Canada: Nfld., NS, Que., Ont., Alta., B.C., Yukon; Northwestern USA: Alaska, Oreg., Wash. (grown experimentally at Palmer, Alaska, but not very winter hardy, W.W. Mitchell, personal communication 1994); Southwestern USA: Ariz., Calif., Nev.; Rocky Mountains USA: Colo., Idaho, Utah; North Central USA: Ill., Minn., Mo., Okla., Wis.; South Central USA: Tex.; Northeastern USA: Mich., N.Y., Vt.; Southeastern USA: Ala., Ark., Ga., Ky., La., Md., N.C., Tenn., W.Va.

Classification. Subg. Schedonorus (Beauv.) Peterm.

Notes. The transfer of this taxon to Lolium (Darbyshire 1993) was evaluated in Aiken et al. (1997).

Markgraf-Dannenberg (1980) recognized five subspecies within F. arundinacea, separated on the characters of panicle shape (lax or dense), spikelet size, (5–9 mm versus 10–12 mm), glume shape (subulate versus lanceolate) and lemma apex (dentate, unawned, acuminate or awned). Herbarium specimens suggest that at least some of the subspecies have been introduced to North America but how extensively is not known.

Illustrations. • Line drawing. Illustration from Scribner (1898) as F. elatior arundinacea. REED FESCUE. The notes accompanying the description state, "Introduced here and there, District of Columbia, Michigan, Utah, Oregon etc." In 1996, it has a very widespread distribution. • Ciliate auricles of F. arundinacea. Ciliate auricles of F. arundinacea. Young leaves with well developed auricles are ciliate in F. arundinacea and glabrous in F. pratensis. The cilia and even the auricles are often lost or sparse in older leaves of herbarium specimens. • Contrasting auricle characters of F. arundinacea and F. pratensis. Contrasting auricle characters of F. arundinacea and F. pratensis. Left, F. pratensis, auricles glabrous. Right, F. arundinacea, auricles ciliate. • Contrast of inflorescences at anthesis. Contrast of inflorescences at anthesis. Left, inflorescence of F. pratensis showing the lowest node having a single spikelet and a short branch that may have 2–4 spikelets. Right, inflorescence of F. arundinacea showing the lowest node having two branches, each with several spikelets. • Contrast of inflorescences after anthesis. Contrast of inflorescences after anthesis. Left, an inflorescence of F. pratensis showing appressed branches at the lowest node. There is a single spikelet right of the main rachis and a longer branch with 3–4 spikelets to the left. Right, an inflorescence of F. arundinacea. The branches are not appressed after anthesis, and the way that a pair of branches is borne towards one side of the rachis is characteristic. • Herbarium specimen: NAU. Herbarium specimen of F. arundinacea with vegetatively proliferating spikelets.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations with detailed captions, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Aiken, S.G., Dallwitz, M.J., McJannet, C.L. and Consaul, L.L. 1996 onwards. Festuca of North America: descriptions, illustrations, identification, and information retrieval. Version: 14th February 2019. delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).

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