Festuca of North America
| Festuca of North America | |
Nomenclature
Fl. Alaska and Yukon 2: 246. 1942. Type: Canada. Arctic sea-coast, 1825 (?), J. Richardson s.n. Syntype GH!
Festuca richardsonii Hook., Fl. Bor. Am. 2: 250. 1840.
F. rubra subsp. arctica auct. non (Hack.) Govor., Fl. Urala: 127. 1937.
Habit. Plants bluish gray green, (8–)15–40(–50) cm high, not densely tufted (loosely caespitose), tiller bases not stiffly erect, bases purplish or not purplish, horizontal rooting stems present. Vegetative shoots arising outside, or breaking through the base of existing sheaths.
Vegetative morphology. Sheaths glabrescent (trichomes prominent, retrorse, if present), not conspicuous at the base of the plant, remaining entire, not conspicuously splitting between the veins, closed more than half their length. Collars glabrous. Auricles absent. Ligules 0.1–0.4 mm long, ciliate. Leaf blades 3–25 cm long, erect, stiffish. Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous. Leaf blades plicate; 0.5–0.71–1.1 mm wide, 0.7–1.12–2 mm deep. Veins 5–8. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed, in discrete, relatively narrow strands opposite the veins. Ribs 5 (well defined). Uppermost culm leaf sheaths not inflated. Flag leaf blades (1.5–)2–4(–6) cm long. Culm nodes never exposed or becoming exposed, 1 when visible; internodes glabrous.
Floral morphology. Inflorescence (2–)3–5(–7) cm long. Inflorescence branches at the lowest node 1–2, appressed after anthesis, 0.4–1.3 cm long. Rachis angular in cross section, trichomes over the entire surface. Spikelets aggregated towards the ends of the branches; 1–4 on the longest branches; (6–)7–8 mm long, 1.5–3 mm wide. Proliferating spikelets absent (usually, samples with proliferating spikelets are synonymous with F. prolifera var. laesiocarpa Fernald. One living plant brought into Dept. of Agriculture, Ottawa, from the Yukon (W.J. Cody & J..H. Ginns 31787, DAO.) produced normal inflorescences in the spring and inflorescences with proliferating spikelets in the fall for at least two seasons, when grown outside at the Agriculture Canada, Central Experimental Farm, in Ottawa). Florets 2–7. Glumes unequal, with trichomes (scabrous or with long, whitish trichomes), vestiture over most of the outer surface, margins not ciliate. First glume 1.5–3 mm long, veins 1. Second glume shorter than the first lemma, 3–4.8 mm long, veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma 5–6.5 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, with trichomes (similar in distribution to trichomes on the glumes), trichomes over the entire surface; apex entire. Lemma awn 0.2–1.6 mm long. Palea 4.5–6 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous or ciliate, 0.9–1.1 mm long. Anthers 2.7–3.7 mm long. Ovary apex glabrous. Caryopsis 2–2.5 mm long.
Cytology. 2n = 42.
Habitat and Distribution. Native; arctic and alpine. Greenland; Canada: Labrador, NS, Que., Ont., Man., Sask., Alta., Franklin District (NWT), Keewatin District (NWT), Mackenzie District (NWT), Yukon; Rocky Mountains USA: Mont., Wyo.
Classification. Subg. Festuca L.
Notes
Tzvelev (1976) questioned whether this is the same taxon as F. rubra subsp. arctica. Alexeev (1985) placed F. rubra subsp. richardsonii into synonymy with subsp. arctica. While Aiken and Darbyshire (1990) recognized F. richardsonii, Aiken et al. (1992) discussed reasons for recognizing the taxon as a subspecies, but did not study Eurasian specimens.
Festuca rubra subsp. richardsonii has limited distribution in the western arctic islands, with several records from Victoria Island and small islands nearby. The collection from Melville Island S.A. Edlund 379A was from an area well used by muskoxen. The suggestion that it has been found on Devon Island at Truelove Inlet, was made by A. Elveakk, University of Tromso, but no voucher has been seen (personal communicaton 1991).
Illustrations
• Field grown plants. Plants of F. rubra subsp. richardonsii in an experimental plot at the Central Experimental Farm, Ottawa. The upper plant is F. rubra and the lower plant is F. rubra subsp. richardonsii, transplanted to Ottawa, from the Yukon. • Leaf anatomy. Leaf cross section of F. rubra subsp. richardonsii. Leaf blades are 0.5–0.71–1.1 mm wide and 0.7–1.12–2 mm deep, with 5–8 veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma are well developed, in discrete, relatively narrow strands opposite the veins. There are 5 well defined ribs. • Syntype specimen: GH. Syntype specimen of F. rubra subsp. richardonsii collected from the Arctic sea-coast, 1825 (?) J. Richardson s.n. GH. • Syntype specimen: NY. Syntype specimen of F. rubra subsp. richardonsii collected from the Arctic sea-coast, J. Richardson s.n., 1825 (?). • 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).
