Festuca of North America
| Festuca of North America |
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Nomenclature
Mantissa 2: 646. 1827. F. brevifolia R. Br. Chloris Melvilliana: 31. 1823, non Muhlenberg, Descr. Gram. 167. 1817. F. ovina var. brevifolia (R. Br.) S. Watson in King, Geol. Explor. Forth. Parall. Bot. 5: 389. 1871. F. ovina subsp. brevifolia (R. Br.) Hack. Bot. Centralbl. 8: 406. 1881. F. ovina subsp. brachyphylla (Schult. & Schult. f.) Piper, Contrib. U.S. Natl. Herb. 10: 27. 1906. F. ovina var. brachyphylla (Schult. & Schult. f.) Hitchc. U. S. Dep. Agric. Misc. Publ. 200: 75, 876. 1951. Type: Canada. N.W.T.: Melville Island, collected on the W.E. Parry Expedition, 1819–1820, J. Edwards s.n. Lectotype: BM! (Frederiksen 1977).
F. brachyphylla forma flavida Polunin, Bull. Natl. Mus. Canada 92 (Biol. Ser. 24): 90. 1940. Type: Canada. N.W.T.: Baffin Island, Lake Harbour, 62°49'N, 69°55'W, 25–26 August 1927, M.O. Malte s.n. GH!
Habit. Plants yellowish green or bluish gray green or deep green (even reddish or very pale green in forma flavida), 5–35(–55) cm high (tall forms are found among specimens collected in Alaska, and from nutrient enriched sites in the Canadian Arctic. They developed in Edmonton, Alberta, when short plants from the Rocky Mountains, were grown at Ellerslie Experimental Station. Vouchers at DAO), densely tufted or not densely tufted, tiller bases stiffly erect (usually) or not stiffly erect (rarely), bases purplish or not purplish, horizontal rooting stems absent. Vegetative shoots arising from within existing sheaths, or 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 or remaining entire, not conspicuously splitting between the veins, closed more than half their length (among the sheaths are prophylls 1–2 cm long, with trichomes on the veins). Collars glabrous. Auricles represented by distinct, erect, swellings. Auricular cilia absent. Ligules 0.1–0.3 mm long, ciliate (erose). Leaf blades (2–)10–20 cm long, erect, stiffish (leaves of arctic plants usually have limited sclerenchyma). Adaxial blade surfaces with trichomes (usually sparsely scaberulous), abaxial blade surfaces glabrous (but sometimes developing obvious trichomes, especially towards the leaf tips, and in moist habitats). Leaf blades plicate; 0.35–0.44–0.65 mm wide, (0.3–)0.55–0.75–0.8(–0.95) mm deep. Veins 3–5(–7). Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed, in discrete, relatively narrow strands opposite the veins. Ribs 1 (well defined, 2–4 variously defined). Uppermost culm leaf sheaths not inflated (0.6–1.7 mm wide, but not appearing inflated, cf. F. hyperborea). Flag leaf blades 0.2–1.5 cm long. Culm nodes becoming exposed or never exposed, 1 (when visible); internodes glabrous, or scabrous-hirsute (or sparsely puberulent, the few hairs stiff and antrorse).
Floral morphology. Inflorescence 1.5–4(–5.5) cm long (culms usually 2–3 times longer than the basal leaves). Inflorescence branches at the lowest node 1, appressed after anthesis (often spike-like), 0.2–1.2 cm long. Rachis angular in cross section, trichomes over the entire surface. Spikelets aggregated towards the ends of the branches (if applicable, often only one spikelet per rachis node); 1–4 on the longest branches; 4–8.5 mm long, 1.5–2.5 mm wide. Proliferating spikelets absent (proliferating spikelets observed rarely, e.g. on a specimen from the N.W.T., DAO 344631. It may be that proliferating plants of this species are sometimes included in F. viviparoidea). Florets 2–4(–6). Glumes unequal, glabrous or with trichomes, vestiture at the apex only, margins ciliate. First glume 1.2–3.3 mm long, veins 1. Second glume shorter than the first lemma, (2.4–)2.9–4.6 mm long, veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma 3–5.2 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes, trichomes on the upper portion only; apex entire. Lemma awn 0.8–3.5 mm long. Palea 3–5.5 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous, 0.7–0.9 mm long. Anthers (0.5–)0.7–1.1(–1.3) mm long. Ovary apex glabrous. Caryopsis 2 mm long (ca).
Cytology. 2n = 28, 42, 44 (?).
Habitat and Distribution. Native; arctic, or alpine. Circumpolar, most commonly occurring on sandy beaches, dry eroding cliffs around fox dens, or owl perches, but occasionally growing through deep moss in the standing water of wet fens or adjacent to tundra pools. The first author has twice observated such plants on Ellesmere Island, N.W.T. Greenland; Canada: Labrador, Nfld., Que., Ont., Man., Sask., Alta., B.C., Franklin District (NWT), Keewatin District (NWT), Mackenzie District (NWT), Yukon; Northwestern USA: Alaska, Oreg., Wash.; Rocky Mountains USA: Mont., Wyo.; Northeastern USA: Vt.
Classification. Subg. Festuca L.
Notes
This species is phenotypically plastic and responds dramatically to additional nutrients in an environment. Plants grew to 55 cm tall when they were moved from exposed sites in the Rocky Mountains of Alberta to Ellerslie Experimental Station, near Edmonton, Alberta. There they were grown in rich black soil in a transplant experiment (voucher specimens at DAO). Festuca brachyphylla occupies the widest range of habitats of any of the North American arctic taxa.
Whether distinctions between F. brachyphylla and F. saximontana Rydb. deserve species status has been debated. Gleason and Cronquist (1991) treated F. saximontana as a variety named F. brachyphylla var. rydbergii (St.-Yves) Cronquist. The taxonomic status of specimens of F. brachyphylla from the Canadian Arctic has been considered by Aiken et al. (1992, 1993, 1994, 1995), who found the results of SDS-PAGE (sodium dodecylsulphate polyacrylamide gel electrophoresis) analyses of seed proteins and isozyme studies provided additional evidence to justify treating these taxa as species. The type specimen was collected on Melville Island, in the Canadian Arctic Archipelago, 74°46'N, 110°46'W, and specimens from this island are hexaploid (Mosquin and Hayley 1966). These authors also reported a tetraploid collection from the same location. The voucher specimen for the tetraploid, at DAO, was examined by S.G. Aiken (1994) and annotated as F. hyperborea Holmen ex Frederiksen.
Illustrations
• "Brunette" form. The genotypic "brunette" form of F. brachyphylla subsp. brachyphylla showing deep purple-brown inflorescences and the conspicuous remains of the previous season's dead leaves, photographed at Iqaluit, Baffin Island, N.W.T. • Forma flavida at Baffin Island, N.W.T.. The forma flavida of F. brachyphylla subsp. brachyphylla. Left, forma brachyphylla. Right, genotypically albino plants of forma flavida, with yellow green leaves and pale yellowish inflorescences. Photographed at McCormick Inlet, Baffin Island, N.W.T. • "Red head" form. Conspicuously red plants of F. brachyphylla subsp. brachyphylla. The redness appears to be a phenotypic colour transition stage for plants with purple inflorescences, towards the end of the summer. Plants growing at the Causeway, Iqaluit, Baffin Island, N.W.T. • Variation in plant height. Plants of F. brachyphylla lined up to show variation in plant height, total size, and colour found within 100 m of each other. The collection was made on Baffin Island, N.W.T. at Cormick Bay, along the beach. Genetic factors appear to explain the paler green plants. The deep blue green plants may well have received additional nitrogen from random sources. • Leaf anatomy. Leaf cross section of F. brachyphylla subsp. brachyphylla. Plicate leaf blades are 0.35–0.44–0.65 mm wide and (0.3-)0.55–0.75–0.8(-0.95) mm deep, with 3–5(-7) veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma strands are poorly developed, in discrete, relatively narrow strands opposite the veins. There is one well defined rib and 2–4 variously defined ribs. • Habitat photograph of Causeway, Iqaluit, Baffin Island, N.W.T.. General view of habitat disturbed by human influences, taken of the Causeway at Iqaluit, Baffin Island, N.W.T., where the picture of the "red head" form of F. brachyphylla subsp. brachyphylla was taken (white box, foreground). • Type specimen of forma flavida: GH. Type specimen of F. brachyphylla subsp. brachyphylla forma flavida. Canada, N.W.T., Baffin Island, Lake Harbour. 25–26 Aug. 1927. M.O. Malte, s.n. GH!. • 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).
