Festuca of North America


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

Festuca subverticillata (Pers.) E. B. Alexeev



Novosti Sist. Vyssh. Rast. 17: 52. 1980. Poa subverticillata Pers., Syn. Pl. 1: 92. 1805. Poa laxa Lam., Tabl. Encycl. Méth. Bot. 1: 183. 1791, non Haenke in Jirasek, Beob. Riesengeb. 118. 1791. Type: U.S.A. Virginia. Holotype: P (photocopy!).

Panicum divaricatum Michx., Fl. Bor. Am. 1: 50. 1803. nom. illeg., non L. Syst. Nat. Ed. 10. 2: 871. 1759. nec Festuca divaricata Desf. Fl. Atlanta 1: 89, Pl. 22. 1798. Panicum debile Poir. in Lam., Encycl. Méth. Bot. Suppl. 4: 283. 1816, non Desf., Fl. Atlant. 1: 59. 1798. Panicum patentissimum Roem. & Schult., Syst. Veg. 2: 448. 1817, non Desf. ex Poir., in Lam. Encycl. Suppl. 4: 283. 1816. Poa brachiata Desv., Opusc. Sci. Phys. Nat.: 100. 1831. Type: U.S.A. Carolina. Hab. in excelsis montibus umbrosis Carolinae. Holotype: P.

Festuca obtusa Bieler, Pl. Nov. Herb. Spreng. Cent.: 11. 1807. Schedonorus obtusus (Bieler) Roem. & Schult., Syst. Veg. 2: 710. 1817. Type: U.S.A. Pennsylvania: Muhlenberg. "In Muhlenberg's Herbarium in the Philadelphia Academy of Sciences are specimens labelled F. nutans and F. sylvatica obtusa. Apparently both these are herbarium names of Muhlenberg, which were first published by Sprengel. Both these specimens are clearly referable to the common eastern plant which has so long gone under the name of Festuca nutans" (Piper 1906).

Panicum gracilentum Poir. in Lam., Encycl. Méth Bot. Suppl. 4: 276. 1816. Type: Cultivée au Jardin des Plantes, Paris. Holotype: P?

Poa festucoides Le Conte ex Torrey in Eaton, Man. Bot. ed. 2: 367. 1818. Type: U.S.A. New York: Le Conte. Holotype: NY?

Festuca pseudoduriuscula Steud., Syn. Pl. Glum. 1: 312. 1854. Type: U.S.A. Texas: Drummond, 398. Holotype: P.

"Festuca nutans var. palustris Muhlenberg" Descr. Gram. 166. 1817. "From Muhlenberg's brief description this is merely a form of F. obtusa. It can scarcely be F. shortii to which Wood referred it. There is nothing so labelled in Muhl. Herbarium" (Piper 1906). ""Varietas palustris..." this word not in italics, not proposed as var., merely mention of wet-ground form" (Chase & Niles 1962).

Festuca obtusa forma pilosifolia Dore in McNeill & Dore, Naturaliste Canad. 103: 560. 1977. Type: Canada. Ontario: Kent Co., New Fairfield, historic site on Hwy. 2. n. side of Thames River, wet bottomland hardwoods, 11 June 1960, P.F. Maycock & O.B. Maryniak 6437. DAO!

Habit. Plants deep green, (40–)50–100(–130) cm high, not densely tufted (leaves mainly on the culm), tiller bases stiffly erect, bases purplish or not purplish, horizontal rooting stems absent. Vegetative shoots arising outside, or breaking through the base of existing sheaths.

Vegetative morphology. Sheaths glabrous or with trichomes (that are retrorse, 1–4 mm long), not conspicuous at the base of the plant, splitting between the veins, open more than half their length. Collars glabrous. Auricles absent. Ligules 0.3–1 mm long, ciliate (sparsely). Leaf blades 10–30 cm long, more or less lax. Adaxial blade surfaces glabrous or with trichomes (long trichomes present in forma pilosifolia Dore), abaxial blade surfaces glabrous. Leaf blades flat, (3–)4–10 mm wide. Veins 16–24 (the intercostal region is 2–3 times the width of the veins). Adaxial to abaxial sclerenchyma strands present. Abaxial sclerenchyma poorly developed, in discrete, relatively narrow strands opposite the veins. Uppermost culm leaf sheaths not inflated. Flag leaf blades 10–20 cm long. Culm nodes becoming exposed, 3–4; internodes glabrous.

Floral morphology. Inflorescence 10–25(–30) cm long. Inflorescence branches at the lowest node 2 (usually) or 3 (pulvinate at the base), spreading (reflexed at maturity), 1.5–13.5 cm long. Rachis angular in cross section, trichomes mainly on the ridges (usually) or trichomes over the entire surface (sparsely). Spikelets loosely scattered in an open panicle with slender branches (spikelets borne towards the ends of the branches); 2–7 on the longest branches (often widely separated on the lower branches, sometimes overlapping slightly towards the ends of the branches); 4–6 mm long, 2–4 mm wide (lanceolate in bud). Proliferating spikelets absent (usually, a collection from Arkansas, MO 1207326, has a few proliferating spikelets). Florets 2–4(–5). Glumes unequal, with trichomes (longer in forma pilosifolia), vestiture at the apex only, margins ciliate. First glume 2–3(–3.5) mm long, veins 1. Second glume shorter than the first lemma, 2.5–4(–4.4) mm long, veins 3. Rachilla internodes glabrous, or nearly so. Lemma callus not elongated. Lemma 3.2–4.7 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes, trichomes over the entire surface (varying from scaberulous to scabrous); apex entire. Lemma awn absent. Palea 3.5–5 mm long (as long or slightly longer than the lemma), glabrous between the keels. Lodicules with marginal teeth, glabrous. Anthers 1.01–1.6(–2.2) mm long. Ovary apex pubescent. Caryopsis 3.8–4.2 mm long.

Cytology. 2n = 42.

Habitat and Distribution. Native; forest and woodland. Canada: NS, NB, Que., Ont., Man.; North Central USA: Iowa, Ill., Kansas, Minn., Mo., Nebr., N. Dak., Okla., Wis.; Northeastern USA: Ind., Mass., Maine (?), Mich., N.H., N.J., N.Y., Ohio, Pa.; Southeastern USA: Del., Ga., Miss, N.C., S.C., Tenn., Va., W.Va.

Classification. Subg. Subulatae (Tzvelev) E. B. Alexeev, sect. Obtusae E. B. Alexeev.


Alexeev (1980, 1985) used the name F. subverticillata for this species but did not explain his reasons, beyond listing basic synonymy. A detailed, unpublished study of the nomenclature by S. J. Darbyshire, Department of Agriculture Canada, and his discussions with the late A. Cronquist, New York Botanical Gardens, resulted in acceptance of the name F. subverticillata (Aiken and Darbyshire 1990, Gleason and Cronquist 1991). Aiken and Lefkovitch (1993) suggested characteristics on which this species is most reliably separated from F. paradoxa Desv. (see notes for that species).


• Inflorescence branch with spikelets at anthesis. A plant of F. subverticillata showing an inflorescence branch with spikelets at anthesis. The branch has 5 spikelets, that do not overlap. The spikelet, second from the right, is open in anthesis. • Inflorescence pre-anthesis. Pre-anthesis inflorescence of F. subverticillata showing lower branches slightly reflexed and borne in pairs that are separated by a wide angle. Note relatively few spikelets per branch. • Inflorescence pre-anthesis. Pre-anthesis inflorescence of F. subverticillata showing lower branches slightly reflexed and borne in pairs that while separated by a wide angle, arise from one side of the rachis. • Habitat and inflorescences "shelling out". Inflorescences of F. subverticillata that are almost erect at anthesis, droop under the weight of seeds to be almost parallel with the forest floor. Many of the spikelets have shed some or all of their seeds. • Inflorescences after seed set. Inflorescence branches of F. subverticillata become strongly reflexed when spikelets are heavy with seeds. Most of the spikelets have shed all of their seeds. • Distribution map

The interactive key provides access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, and summaries of attributes within groups of taxa.

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: 19th October 2005. http://delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).