Festuca of North America

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

Festuca lenensis Drobow

Nomenclature

Tr. Bot. Inst. Akad. Nauk SSSR 14: 158. 1915. Type: Russia: Prov. Jakutsk, slope of the Lena River, near Kjatczinskoje, 6 June 1914, G. I. Dolenko 103. Lectotype LE! (Tzvelev 1984).

F. auriculata Drobow, Tr. Bot. Inst. Akad. Nauk SSSR 14: 159. 1915, sensu Aiken and Darbyshire (1990).

F. ovina subsp. alaskana Holmen, Bot. Not. 117: 115. 1964, pro parte, quoad descr. sed non typus.

Habit. Plants bluish gray green, (7–)10–30(–50) cm high, densely tufted, tiller bases stiffly erect, bases not purplish, horizontal rooting stems absent. Vegetative shoots arising from within existing sheaths.

Vegetative morphology. Sheaths glabrous or glabrescent or with trichomes, conspicuous at the base of the plant, persisting for more than 1 year, remaining entire, not conspicuously splitting between the veins, closed more than half their length. Auricles represented by distinct, erect, swellings. Auricular cilia absent. Ligules 0.2–0.4 mm long, ciliate. Leaf blades 4–9(–13) cm long, erect, stiffish. Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous or with trichomes (trichomes glabrescent, conspicuously long when present). Leaf blades plicate; 0.4–0.52–0.7 mm wide, 0.65–0.79–1 mm deep. Veins 5–7. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma poorly developed or well developed (sclerenchyma in three areas only, at the midvein and leaf margins, sometimes strongly developed). Ribs 1 (well developed, 2–4 variously defined). Uppermost culm leaf sheaths not inflated. Flag leaf blades 0.3–2 cm long. Culm nodes becoming exposed or never exposed, 1 (when visible); internodes glabrous, or scabrous-hirsute (near inflorescence, elsewhere glabrous).

Floral morphology. Inflorescence 1.5–4(–5.5) cm long. Inflorescence branches at the lowest node 1–2, appressed after anthesis, 0.1–0.7 cm long (pedicels). Rachis angular in cross section, trichomes mainly on the ridges or trichomes over the entire surface. Spikelets 1 on the longest branches; (5–)7–9(–11) mm long, 2.5–5 mm wide. Proliferating spikelets absent. Florets (2–)4–5(–7). Glumes unequal, glabrous or with trichomes, margins ciliate. First glume 2.5–3.6 mm long, veins 1. Second glume shorter than the first lemma, 3–4.5 mm long, veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma 3–6 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 1–2.6(–3) mm long. Palea 3.5–5.5 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous, 0.7–0.9 mm long. Anthers 2.3–3.7 mm long. Ovary apex glabrous. Caryopsis 2–2.5 mm long.

Cytology. 2n = 14.

Habitat and Distribution. Native; arctic, or alpine. Canada: Alta., Mackenzie District (NWT), Yukon; Northwestern USA: Alaska.

Classification. Subg. Festuca L.

Notes

Festuca lenensis has been known as: F. ovina var. alaskana Holmen (Hultén 1968, Porsild and Cody 1980), F. auriculata Drobow (Frederiksen 1983), F. lenensis Drobow (F. ovina subsp. alaskana Holmen pro parte; Aiken and Darbyshire 1990).

As a result of isozyme analyses and the examination of the type specimens of F. auriculata and F. lenensis, the name F. agg. auriculata was used by Aiken et al. (1993) following Tzvelev (1976). The study was based on specimens from the Northern Yukon and the suggestion was made that plants from this location may have been sufficiently isolated from Russian plants to have speciated to a distinct subspecies. No further work has been done on this suggestion and the name F. lenensis is used, as the Yukon plants are considered closer to the type of that name. Three collections from Alaska sent in by David Murray, University of Alaska, had the leaf anatomy of F. auriculata s.s., but they had grown in very harsh environments. Until further evidence is available, they are considered to be stunted plants of F. lenensis that had a very short growing season.

In some DELTA analyses the similarity of F. lenensis to the introduced "pseudovina" (F. valesiaca Schleich. ex Gaud. s.l.) of the grass seed trade is evident. Both are diploid species (possibly sister taxa) that occur naturally in the fescue steppes of the southeastern Altai where they are valuable forage, particularly in the spring (Dulepova 1986, Namzalov 1986).

Illustrations

• Plant habit. Festuca lenensis at anthesis. Note spikelets are not appressed to the rachis. Within 24 hours the spikelets on the same plant had become appressed to the rachis. • Leaf anatomy. Leaf cross section of F. lenensis. Leaf blades are 0.4–0.52–0.7 mm wide and 0.65–0.79–1 mm deep, with 5–7 veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma strands are poorly developed or well developed. There are sclerenchyma in 3 areas only, at the midvein and leaf margins, sometimes strongly developed. There is one well developed rib and 2–4 variously defined ribs. • Habitat in the Northern Yukon. Left, habitat photograph with grey-green grasses near the orange flagging tape (white box), growing on argillite outcrop near Alaskan/Yukon border. Right, plant collected at anthesis, showing spikelets spreading from the inflorescence rachis. • Position of inflorescence branches. Left, inflorescences at anthesis with spikelets spreading away from the inflorescence rachis. Plants photographed in the late afternoon. Right, plants from the same collection photographed the following morning. With the digging up of the specimens and keeping them overnight the inflorescence branches had become appressed to the rachis. This character which had been used by Tzvelev (1976) to separate F. auriculata from F. lenensis is considered to reflect on the stage of anthesis plants are at when collected. • Plant habitat in Barren Grounds. Festuca lenensis occurs on rocky slopes, that most other barren ground species do not inhabit. In the "barren grounds" of the Yukon, there are few suitable habitats for grasses. They usually cannot compete with the dense vegetation cover of the heath plants (red in the fall), willows, (green) and sedges (yellow). • The Yukon Shingle Point. The Yukon Shingle Point. Gravel shoreline near the site where the specimen considered to be F. auriculata by Alexeev (1985) was collected. The exact location has been destroyed and no evidence of the species in the adjacent area was found in an extensive 2 day search in 1988 by S.G. Aiken. • Lectotype specimen: LE. Type specimen of F. lenensis from Leningrad. Tr. Bot. Inst. Akad. Nauk SSSR 14: 158. 1915 former USSR: Prov. Jakutsk, slope of the Lena River, near Kjatczinskoje, 6 June 1914, G. I. Dolenko 103. Lectotype LE! (Tzvelev 1984). • Habitat of plants with, contrasting height forms. Plants of F. lenensis of contrasting heights where collected from this habitat. A shallow hollow towards the centre of this picture had tall plants more than 20 cm high growing in the bottom of the hollow which had additional moisture and nutrients from accumulated debris. Short plants were on the adjacent sun baked tundra. The temperature on the collection day was near 30C. The herbarium voucher is shown in the next image. • Herbarium specimen, contrasting height forms: CAN. Height forms of F. lenensis found growing within a metre of each other in the Yukon. The tall plant was growing in a sheltered hollow with additional moisture and nutrients. The short plants were growing on adjacent sun baked tundra. The temperature on the collection day was near 30 degrees Celcius. Plant less than 20 cm high had been used by Tzvelev (1976) to separate F. auriculata from F. lenensis. Height differences are considered to depend on the environment in which the plants are growing and the phenotypic plasticity of F. lenensis. • Controversial Specimen: DAO. Duplicate of a specimen annotated as F. auriculata and collected in the Northern Yukon at Shingle Point, that Alexeev (1985) considered to be evidence of F. auriculata occurring in Canada. • 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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