Festuca of North America

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

Festuca edlundiae S. Aiken, Consaul & Lefkovitch

Nomenclature

Syst. Bot. 20: 381. 1995. Type: Canada. N.W.T.: Bathurst Island, Polar Bear Pass, 75°43'N, 98°12'W, marine worked carbonate ridge, on the north side of a broad valley west of the Goodsir River, 11 August 1985, S.G. Aiken 3949. Holotype: CAN 502531! Isotype: DAO 460223!

Habit. Plants yellowish green, (2.5–)5.5–10(–14) cm high, densely tufted, tiller bases stiffly erect or not stiffly erect, bases not purplish, horizontal rooting stems absent. Vegetative shoots arising from within existing sheaths.

Vegetative morphology. Sheaths glabrous or with trichomes, conspicuous at the base of the plant, persisting for more than 1 year, remaining entire, not conspicuously splitting between the veins, open more than half their length (sheaths often opening and drying flat and conspicuous as yellow straw within the plant tussock; fragile prophylls, with trichomes on the veins split early). Collars glabrous. Auricles represented by distinct, erect, swellings. Auricular cilia absent. Ligules 0.2–0.5 mm long, ciliate. Leaf blades (1.5–)3–6(–9) cm long, more or less lax. Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous or with trichomes (hairs visible at 40×). Leaf blades plicate; 0.5–0.66–0.9 mm wide, 0.8–0.92(–1.1) mm deep. Veins 5–7. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed, in discrete, relatively narrow strands opposite the veins. Ribs 5 (well developed). Uppermost culm leaf sheaths somewhat inflated (0.8–1.5 mm wide). Flag leaf blades 0.3–1.25 cm long. Culm nodes never exposed (one unusually etiolated specimen was found with a single node visible); internodes glabrous.

Floral morphology. Inflorescence 1.5–3.5 cm long. Inflorescence branches at the lowest node 1–2, appressed after anthesis, 0.4–0.7 cm long. Rachis angular in cross section, trichomes mainly on the ridges. Spikelets aggregated towards the ends of the branches; 1–2 on the longest branches; 4.5–8.5 mm long, 3–4 mm wide. Proliferating spikelets absent. Florets 2–6. Glumes unequal, glabrous, margins ciliate. First glume 1.8–3.1 mm long, veins 1. Second glume shorter than the first lemma, 2.9–4.3 mm long (often conspicuously lanceolate and longer than the upper glume of F. hyperborea Holmen ex Frederiksen in the straw of the previous inflorescence. Illustrated in the image library), veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma 3.6–5.2 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes, trichomes on the upper portion only; apex entire (usually). Lemma awn 1.1–2.9 mm long. Palea 3.8–5.5 mm long, distinctly pubescent between the keels (sparse hairs). Lodicules with marginal teeth, glabrous, 0.8–1 mm long. Anthers 0.6–1.1 mm long. Ovary apex glabrous. Caryopsis 2.5–3 mm long (evidence of cleistogamy found on the type specimen).

Cytology. 2n = 28.

Habitat and Distribution. Native; found on calcareous tills. Greenland; Canada: Franklin District (NWT).

Classification. Subg. Festuca L.

Notes

The taxon was first identified as a new species by B. May, University of California at Davis, (personal communicaton 1992), from isozyme analyses (Aiken et al. 1994). The specific epithet honours Dr. Sylvia A. Edlund, for her extensive and intensive contributions to Arctic field work and her studies of vegetation in the Arctic Archipelago over many years. Previously, specimens of F. edlundiae were usually placed in F. hyperborea or F. brachyphylla Schult. & Schult. f. A study of phenotypic plasticity in four species of arctic fescues (Ramesar-Fortner et al. 1995) reported differences in the growth response of F. edlundiae and F. hyperborea under controlled growing conditions.

Illustrations

• Close up of plant. Plant growing in the Northwest Territories, Cornwallis Island, near Resolute Bay on VIP Hill. Photograph by Hugh Gibbins, 1994. • Leaf anatomy. Leaf cross section of F. edlundiae. Leaf blades are 0.5–0.66–0.9 mm wide and 0.8–0.92(-1.1) mm deep, with 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 are 5 well developed ribs. • Habitat at Polar Bear Pass, N.W.T.. Habitat at Polar Bear Pass at the High Arctic Research Station on Bathurst Island, N.W.T., where the type specimen of F. edlundiae was collected. The dominant darker plants, at the base of the ladder to the observation tower (upper white box), are F. baffinensis, the other paler F. plants, closer to the knapsack (lower white box), are F. edlundiae in the type locality for this species. • Habitat on Arctic tundra. Habitat photograph of Arctic tundra at the research station at Polar Bear Pass, Bathurst Island, N.W.T. Flagging tapes in pink and yellow were part of an isozyme experiment that determined that F. edlundiae was genetically distinct from F. hyperborea and not an isozyme form related to microhabitat differences. • Close up of microhabitats. Plants in microhabitats on tundra, adjacent to the High Arctic Research Station at Polar Bear Pass on Bathurst Island, N.W.T. The pink flagging tape is beside a plant growing isolated in the centre of a frost boil, the yellow flagging tape is beside plants growing in dark frost cracks, with other plants and accumulated organic matter. The plants were tagged in the experiment that established that F. edlundiae is a distinct species and not an isozyme ecotype of F. hyperborea (Aiken et al. 1995). At the early stage of the growing season when plants were tagged, no distinctions between the species were visible. The isozyome results and observations later in the season established that more than 80% of the plants studied at the site were F. edlundiae. • Habitat at Resolute, N.W.T.. Habitat photograph taken near VIP Hill (in the distance), Resolute Bay on Cornwallis Island, N.W.T. White plastic bags on the tundra indicate location of a plant of F. edlundiae relative to a plant of F. hyperborea. • Contrast of F. edlundiae and F. hyperborea. A plant of F. hyperborea (left) growing beside F. edlundiae (right) at Resolute, Cornwallis Island, N.W.T. • Holotype specimen: CAN. Holotype specimen of F. edlundiae. Canada. N.W.T., Bathurst Island, Polar Bear Pass, 7543'N, 9812'W, marine worked carbonate ridge, on the north side of a broad valley west of the Goodsir River. 11 Aug. 1985. S.G. Aiken 3949, Holotype: CAN 502531. • 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).

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