Festuca of North America

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

Festuca brevissima Jurtzev

Nomenclature

Bot. Zh. (Leningr.) 57: 645. 1972. Type: Russia: Prov. Magadan, regio Tschukotsky, montes Anadyrsk, in vicin. lacus Eljgygtgyn, ripa australis, in declivibus australi-occidentalibus, 20 July 1968, A. Korobkov & B. Jurtzev K-6154. Holotype: LE, Isotype: LE!

F. ovina subsp. alaskana Holmen, pro parte, quoad typo, sed non descr. Bot. Not. 117: 115. 1964. Type: U.S.A. Alaska: Brooks Range, 69°20'N, 145°W, Lake Peters, 7 July 1961, K.A. Holmen 901. Isotype: C.

F. brevissima forma pallida (Holmen) Frederiksen, Nord. J. Bot. 2: 531. 1982. Basionym: F. ovina subsp. alaskana forma pallida Holmen, Bot. Not. 117: 115. 1964. Type: U.S.A. Alaska: Cape Sabine, 68°53'N, 164°35'W, 1960, Holmen K.A. 866.

Habit. Plants yellowish green or deep green, (2.5–)10–15(–18) cm high, densely tufted (tufts separated into groups of shoots surrounded at the base by more or less numerous leaf sheaths), tiller bases stiffly erect, bases not purplish, horizontal rooting stems absent. Vegetative shoots arising from within existing sheaths.

Vegetative morphology. Sheaths glabrous, not conspicuous at the base of the plant, remaining entire, not conspicuously splitting between the veins (slowly disintegrating after more than one year), closed more than half their length (Frederiksen, 1978; fibrillose prophylls to l cm long occur among the sheaths and split early in the growing season). Collars glabrous. Auricles represented by distinct, erect, swellings. Auricular cilia absent. Ligules 0.3–0.5 mm long, ciliate. Leaf blades 1–5 cm long, erect, stiffish. Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous. Leaf blades plicate; 0.4–0.55–0.75 mm wide, 0.4–0.68–0.8 mm deep. Veins 5–7(–9). Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed ((3-)5–7 fine sclerenchyma strands, rarely well developed), in discrete, relatively narrow strands opposite the veins. Ribs 1–6 (usually well defined). Uppermost culm leaf sheaths not inflated (usually). Flag leaf blades 0.2–1 cm long. Culm nodes never exposed or becoming exposed (rarely), 1 (if visible); internodes glabrous (sometimes scabrous 1–2 cm below the panicle).

Floral morphology. Inflorescence 0.7–2.5(–5) cm long (depauperate with (2-)3–5(-14) spikelets). Inflorescence branches at the lowest node 1, appressed after anthesis, 0.1–1 cm long (Frederiksen 1978, stated that "this species is morphologically very similar to F. brachyphylla but differs in having an open panicle with spreading branches at the time of anthesis). Rachis rounded in cross section or angular in cross section (somewhat wiry), trichomes mainly on the ridges. Spikelets aggregated towards the ends of the branches; 1–3 on the longest branches (usually with a single spikelet); 4–7 mm long, 1.8–2.5 mm wide. Proliferating spikelets absent (one candidate specimen seen, but the plants are too immature to be sure of the identification). Florets 2–4. Glumes unequal, glabrous or with trichomes (that are scaberulous, if present), vestiture at the apex only (if applicable, trichomes on the main vein), margins ciliate. First glume 2.5–3.2 mm long, veins 1. Second glume shorter than the first lemma, 3.2–4.8 mm long, veins 1–3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma (3.9–)4–5(–5.5) 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 0.5–2.5 mm long. Palea 3.8–4.5 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous, 0.6–0.8 mm long. Anthers 0.9–1(–1.2) mm long. Ovary apex glabrous. Caryopsis 2–2.2 mm long.

Cytology. 2n = 14.

Habitat and Distribution. Arctic, or alpine. In North America, F. brevissima grows on exposed, dry, rocky tundra often on the tops of mountains. In the Northern Yukon near the Alaskan border, in 1990, it was found at higher altitudes and in more exposed habitats than F. lenensis Drobow. Canada: Mackenzie District (NWT), Yukon; Northwestern USA: Alaska.

Classification. Subg. Festuca L.

Notes

Frederiksen (1978) documented that F. ovina subsp. alaskana Holmen is conspecific with F. brevissima, which occurs on both sides of the Bering Strait. Material named as F. ovina subsp. alaskana by North American authors is generally referable to F. lenensis. The anthers of F. ovina subsp. alaskana were originally described as being 2.5–3 mm long, as in F. lenensis, but the type specimen was determined by Frederiksen (1978) to have much shorter anthers and was transferred to F. brevissima.

Unlike F. brachyphylla Schult. & Schult. f., F. edlundiae S. Aiken, Consaul, & Lefkovitch, and F. hyperborea Holmen ex Frederiksen, the panicle branches of F. brevissima spread at anthesis. Frederiksen (1978) indicated that this species differs from F. brachyphylla in being smaller, having shorter flag leaf blades, fewer spikelets, (usually one per branch), and glaucous colour. It differs from F. hyperborea in having erect leaves that may have 7–9 veins, usually longer flag leaves, somewhat longer anthers, and the lanceolate lemmas with erect terminal awns. Other features distinguishing F. brevissima include the thin, wiry rachis that is often slightly curved, the somewhat longer ligule, and the usually attenuate glumes. Length of the flag leaf blade in F. brachyphylla was observed to be extremely variable during field work in the Canadian Arctic Archipelago. The character, shorter flag leaf blades, should be used with caution. Plants of F. brachyphylla occurring in the same areas of North America as F. brevissima usually have well developed flag leaf blades.

Illustrations

• Isotype specimen: LE. Isotype specimen of F. brevissima from Russia. Latin label reads, "Prov. Magadan, regio Tschukotsky, montes Anadyrsk, in vicin. lacus Eljgygtgyn, ripa australis, in declivibus australi-occidentalibus, 20 July 1968, A. Korobkov and B. Jurtzev K-6154". Holotype: LE, Isotype: LE!. • Leaf anatomy. Leaf cross section of F. brevissima. Leaf blades are 0.4–0.55–0.75 mm wide and 0.4–0.68–0.8 mm deep, with 5–7(-9) veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma strands are poorly developed, with (3-)5–7 fine sclerenchyma strands, rarely well developed, in discrete, relatively narrow strands opposite the veins. There are 1–6 ribs, that are usually well defined. • Herbarium specimen, southern Yukon: CAN. Festuca brevissima specimen collected in Yukon: Ogilvie Mountains: mountain east of mile 57–58, on gravel sides of south side of ridge, 31 July 1966. R.T. Porsild 378. • Herbarium specimen: CAN. Controversial herbarium specimen of F. brevissima collected as F. brachyphylla and questioned as being F. hyperborea. A duplicate of this collection, that was sent to LE, was annotated as F. hyperborea by T.V. Petrovsky in 1974. This lead to the suggestion that F. hyperborea occurs in Western Canada, as mapped in Aiken and Darbyshire (1990). Canada, Yukon, Ogilvie Mountains, Mountain east of mile 57–58, in open gravel patches at top of mountain, 31 July 1966. R.T. Porsild 395. The duplicate at LE was annotated as F. brevissima by E. B. Alexeev in Feb. 1981. • Herbarium specimen, northern Yukon: CAN. Festuca brevissima collection from northern Yukon, Buckland Hills, 6919'N, 13935'W, on exposed soil hummocks among rocks. Elev. 457 m. 13 July 1988. S.G. Aiken 88–257A. CAN. • 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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