Festuca of North America
A strong creeping red fescue.
The place of publication of this name has not been found.
F. heteromalla Pourr. Chloris Narbonensis "extrait" republished in Mem. Acad. Roy. Sci. Toulouse 3: 319. 1788. (originally published in 1783). Type: A Nabonne, dans les prés, France.
F. diffusa Dumort. Obs. Gram. Belg. 106. 1824.
The following description was prepared with the help of Martin Dubé in 1990.
Habit. Plants deep green, 34–65 cm high (usually in North America, to 100 cm high in Europe), not densely tufted (laxly caespitose), tiller bases stiffly erect or not stiffly erect, bases purplish or not purplish (often pinkish red), horizontal rooting stems present. Vegetative shoots arising from within existing sheaths, or arising outside, or breaking through the base of existing sheaths.
Vegetative morphology. Sheaths with trichomes (usually), not conspicuous at the base of the plant, splitting between the veins, closed more than half their length. Collars glabrous. Auricles absent. Ligules 0.1–0.5 mm long, ciliate. Leaf blades 10–37 cm long, erect, stiffish or more or less lax. Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous or with trichomes (usually). Leaf blades flat (usually) or plicate (strongly keeled); 0.6–1.05 mm wide, 1–1.5 mm deep. Veins 7–12. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed (strands separate, not very stout, subequal in width), in discrete, relatively narrow strands opposite the veins (sometimes with sclerenchyma on the top of the prominent ribs and a few conspicuously long hairs, Dubé et al. 1987, illustrated in the image library). Ribs 7–9. Uppermost culm leaf sheaths not inflated. Flag leaf blades 5–8 cm long. Culm nodes becoming exposed, 1–3; internodes glabrous.
Floral morphology. Inflorescence 5–10 cm long (9–15 cm, Markgraf- Dannenberg 1980). Inflorescence branches at the lowest node 1–3, spreading (panicle relatively lax and wide), 3–7 cm long. Rachis angular in cross section, trichomes mainly on the ridges (scabrid). Spikelets 3–7 on the longest branches; 7–9.8(–12) mm long (green, glaucous, or more or less violet-tinged). Proliferating spikelets absent. Florets 3–7. Glumes unequal, with trichomes (scaberulous), vestiture at the apex only, margins not ciliate. First glume 2.6–4 mm long, veins 1. Second glume shorter than the first lemma, 3.8–5.2 mm long, veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma (5–)6–7.5 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes (scabrous), trichomes on the upper portion only (and on the marginal nerves); apex entire. Lemma awn 0.65–2.6 mm long. Palea as long as the lemma, distinctly pubescent between the keels. Anthers 2.4–3 mm long. Ovary apex glabrous.
Cytology. 2n = 56.
Habitat and Distribution. Introduced (from northern and central Europe); naturalized and cultivated crop; meadows (and damp places). Canada: Nfld., Que. (Recorded in North America predominantly from Quebec by Martin Dubé, but possibly widespread).
Dubé and Morisset (1983, 1995) prefer to follow Markgraf-Dannenberg (1980) and treat this taxon as a full species. This was partly because there are nomenclatural problems if the taxon is treated as a subspecies, since it is not certain that the subspecies name is valid (M. Dubé, personal communciation 1990). Subspecies status is suggested at this time as it appears to be no more distinct than the other subspecies analyzed in this database.
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).