Festuca of North America
Sp. Pl.: 83. 1753.
L. arvense With.
Habit. Plants yellowish green or bluish gray green, 20–120 cm high, not densely tufted, 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, not conspicuous at the base of the plant, splitting between the veins, open more than half their length. Collars glabrous. Auricles present, claw-like. Auricular cilia absent. Ligules 0.5–2.7 mm long, without cilia. Leaf blades 5–27 cm long, more or less lax. Adaxial blade surfaces with trichomes (scabridulous at the apex and beneath), abaxial blade surfaces glabrous or with trichomes (more or less scabridulous and glossy). Leaf blades flat, 1–2 mm wide. Veins 10–50. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed, in discrete, relatively narrow strands opposite the veins (if present). Ribs well defined. Uppermost culm leaf sheaths not inflated. Flag leaf blades 7–15(–20) cm long. Culm nodes becoming exposed, 3–5; internodes scabrous-hirsute.
Floral morphology. Inflorescence spicate, 5–40 cm long. Rachis internodes cuneate in cross section. Rachis scabridulous. Spikelets alternating on opposite sides of the rachis. Spikelet edges fitting into the rachis. Spikelets 8–28 mm long, 3–8 mm wide. Proliferating spikelets absent. Florets 2–15. First glumes absent (present only on uppermost spikelet of an inflorescence). Glumes unequal (sometimes approaching subequal in uppermost spikelet of an inflorescence), with trichomes (scabridulous), vestiture over most of the outer surface, margins not ciliate. First glume 7–30 mm long (if present), veins 5 (coriaceous). Second glume as long as the first lemma, or almost as long, 7–30 mm long (0.75 –1.5 times as long as the spikelet), veins 5–7. Rachilla internodes 1–2.5 mm long, antrorsely scabrous (minutely scaberulous). Lemma callus not elongated (a short cup-like ridge). Lemma 4.6–8.5 mm long (elliptical to ovate, very turgid at maturity), nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes (scabrous), trichomes on the upper portion only (and margins); apex apically cleft (usually). Lemma awn 0–23 mm long. Lemma and palea becoming indurate. Palea 4.6–8.5 mm long (as long or slightly longer than the lemma), distinctly pubescent between the keels (very scabrous on veins). Lodicules without marginal teeth, glabrous, 1–1.5 mm long. Anthers 3.1–3.5 mm long. Ovary apex glabrous (styles inserted asymmetrically). Caryopsis (3.8–)4.2–7 mm long (2–3 times as long as wide).
Cytology. 2n = 14.
Habitat and Distribution. Introduced (rarely); cultivated crop (in Europe, rarely cultivated in Canada). "Perhaps native in Mediterranean regions; formally widespread in most of Europe as a weed of cereal crops (especially Avena), but now only a casual ruderal in most of N. and C. Europe." Humphries 1980.
Classification. Lolium L.
Plants annual. Data entered for classification studies.
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).