Life span

Perennial, potentially very long-lived.

Growth form

Graminoid herb growing in loose tussocks or dense to loose mats due to horizontal, branched rhizomes, with main branching outside leaf sheaths (extravaginal), typically with rhizome branches (1)2–5(8) cm between aerial shoots. Aerial shoots ascending from rhizome, at base with several prophylls (reduced leaves without or with a short blade). Culms 10–20 cm (occasionally to 35–40 cm), erect, reddish green, very strongly ribbed, smooth throughout or sparsely to moderately scabrous or pubescent just below the panicle. Base of shoots with a few, pale straw-coloured, remaining sheaths from previous years, but not forming a dense cylinder of old sheaths.

Leaf

Leaves filiform, convolute and U-shaped in cross section, or flat (flat leaves mostly associated with culms, filiform leaves with leafy shoots), with discontinuous strings of sclerenchyma (strengthening tissue) and therefore with ca. 6 distinct ribs, glabrous or more rarely sparsely pubescent on the sheaths. Basal leaves up to 10(20) cm long, much shorter than culms, 0.7–1.0 mm broad when convolute, up to 2.5 mm broad when flat. Leaf sheaths closed for ca. 75 % of their length or more. Culm leaves filiform or flat, the uppermost (the 'flag leaf') blade often flat, 2–3(6) cm, attached below the middle of culms. Distinct auricles at the transition between sheath and blade. Ligula 1.5–2.5 mm, truncate, more or less fringed.

Inflorescence and Flower

The units of the inflorescence of Poaceae are the spikelets, nearly always numerous in a panicle or spike-like inflorescence. Spikelets are composed of 2 glumes (bracts for the spikelet) and one or more flowers (the term used below) or rather floral units often named ‘florets’ because we do not know what is the exact flower. A flower or floret is composed of a lemma with 1 mid vein (probably the floral bract), a palea with 2 mid veins (either 2 fused bracteoles or perhaps 2 fused perianth leaves), 3 small organs called ‘lodiculae’ and essential in the opening of the flower at anthesis (possibly transformed perianth leaves or transformed stamens), 3 stamens (mostly), and a gynoecium of 2 fused carpels with 2 feathery stigmas and one seed.

Inflorescence an elongated, moderately dense panicle, 3–5(7) cm long, less than 1/4 the length of (well-developed) culms. Panicle branches short, 2–4 mm, mostly at 5–8 nodes, usually 2 at the lowest node, 1 at the other nodes. Branches smooth, moderately pubescent or scabrous (correlated with degree of pubescence on glumes and lemmas), each branch with 1–3 spikelets. Spikelets 6–8(9) × (1)2.5–3.5 mm, with 4–6 flowers. Bracts (glumes and lemmas) with rounded backs,. Glumes unequal, the lower 2–3 mm, the upper 3–5 mm and ca. 1/2 as long as spikelet, lanceolate, more rarely ovate, with (3)5 distinct veins, glossy, glabrous or with sparse hairs in distal part, violet with a narrow or broad, yellow, hyaline margin or sometimes hyaline throughout (the lower glume), without awn. Lemmas 4–6 mm, broadly to narrowly lanceolate, with mostly 5 distinct veins (but often hidden by pubescence), shiny (but shine usually hidden by pubescence), violet with yellow hyaline margin, in the main form densely pilose with long, soft, white hairs, more rarely with only sparse hairs apically or glabrous, without awn in the main form, with awn up to 1(2) mm in possibly transitional forms to ssp. rubra. Paleas as long as lemmas, scabrous on the veins, otherwise smooth. Anthers well developed, 1.9–2.3 mm.

Fruit

Fruit an achene (with one seed).

Reproduction

Sexual reproduction by seeds; efficient local vegetative reproduction by horizontal rhizomes, producing sometimes huge clones that can disintegrate into several independent plants by soil movement and accidents (screes, erosion, flooding). Wind pollinated. Seed production abundant in most years although they may not ripen (Alsos et al. 2013) or germinate to low percentages (Eurola 1972).

Passive dispersal of fruits inside florets, but the hairy lemmas and scabrous awn may attach to birds and animals and also facilitate some wind dispersal.

Comparison

The fescues of Svalbard belong to several groups, all within the major section Festuca. The Festuca rubra group (including F. rubra. ssp.  richardsonii and F. rubra ssp. rubra) is characterized by both intravaginal and extravaginal branching, the latter resulting in rhizomatous mats, and by several prophylls (see definition above) at the base of the shoots, by leaf sheaths closed for most of their length, and by auricles at the transition between sheath and blade. All the other fescues have only intravaginal branching, resulting in dense tussocks without any runners, no or only a single prophyll, leaf sheaths open almost to base, and almost no auricles.

There have been numerous misidentifications of F. rubra in the Svalbard through times. There is no good reason for that, as long as the specimen in question is identified as a Festuca (rounded backs of glumes and lemmas, acute or awned lemmas, most or all leaves filiform). Even in plants without culms and spikelets, the extravaginal rhizomatous shoot system of F. rubra, with prophylls and absence of sheath cylinder around the bases of shoots, is very different from the tussock system of all the others. However, F. rubra is an extremely polymorphic species, even in Svalbard, and you may find some forms here and there that may be difficult to assign. Particularly confusing is the variation in growth form and in shape and pubescence of glumes and lemmas. Festuca rubra may grow as very loose mats or as quite dense tussocks, probably depending on both genetics and environmental conditions. The variation in shape and pubescence of the glumes and especially the lemmas which vary from shiny glabrous to densely white pilose, needs further study. Several local populations deviate strongly from the standards of the two subspecies. We are not sure whether transitional forms between the subspecies really occur in Svalbard or if they are part of the polymorphy of ssp. richardsonii.

We have divided the material on two subspecies but their characterization is ambiguous. Subspecies richardsonii is usually recognized by its densely pilose lemmas (visible at a good distance with sufficient light) and its lack of awn; ssp. rubra is mostly awned, and even when its lemmas are hairy, they are not densely white pilose. Another difference is found in the panicle structure: ssp. richardsonii has very short branches (very rarely 1 cm) with 1–3 spikelets; ssp. rubra has quite long branches (mostly more than 2 cm) with 4–8 spikelets.

Habitat

Festuca rubra ssp. richardsonii is common in a wide range of vegetation types, especially in meadows and heaths, often as the only grass among Salix polaris, Dryas, and Cassiope. It is common also on more sparsely vegetated ground such as river bars, dry sediment plains and in screes. Not occurring in permanently wet places but tolerates occasional seepage and inundation. There seem to be little relations as to substrate (gravel to silt, acidic to calcareous) or climate. When you find a grass sward of filiform leaves without any culms, the chances are good that you are standing in a mat of F. rubra. This can be confirmed by the U-shaped cross section of the leaves.

Distribution

Found in all zones and sections, on all the four major islands, and also on Prins Karls Forland, Kong Karls Land and Bjørnøya, but not (yet) documented from Hopen. We assume this to be the most common and widely distributed grass in Svalbard. The sparse records from many parts of Svalbard in the map are due to it being too common and trivial to be collected or even noted. Its concentration to certain parts of Svalbard in the map mainly reflects the intensity of collecting.

Outside Svalbard, this is the most widely distributed grass throughout the Arctic, common throughout Eurasia, North America, and Greenland. It also occurs in the northern boreal zones and in mountains farther south.

Comments

Festuca rubra or the F. rubra group (depending on whether you are a 'lumper' or a 'splitter') is one of the taxonomically and morphologically most complicated of all northern grasses (with Poa pratensis s. lat. as a close competitor). Markgraf-Dannenberg (1980; Flora Europaea) accepted ca. 14 species for Europe in a F. rubra group,and within F. rubra s. str. seven subspecies. Soreng et al. (2003) accepted at least eleven subspecies of F. rubra for North America, whereas Darbyshire & Pavlick (2007; Flora of North America) accepted ten subspecies for the same region. The main arctic race, ssp. richardsonii, is one of the more consistently accepted and circumscribed of the races, often accepted as a species in its own right. We have seen transitions, in Fennoscandia and elsewhere, suggesting that rank as a subspecies is the most appropriate. It is consistently hexaploid (2n = 42) throughout most of its range (Svalbard included), whereas some complications may be found in Siberia and Alaska where morphologically deviating octoploids (2n = 56) occur (Elven et al. 2011).

The correct scientific name is still disputed (see Elven et al. 2011). If the plant is considered a species, the name Festuca richardsonii Hook. 1840 has priority well before the often applied name in Russia, F. cryophila V.I.Krecz. & Bobrov 1934. We have inspected the type of F. richardsonii (from Canada, voucher in Kew, London) and confirm it as belonging to the plant in question. If the plant, as here, is considered a subspecies, it becomes more problematic. The combination F. rubra ssp. richardsonii (Hook.) Hultén from 1942 is predated by F. rubra ssp. arctica (Hack.) Govor. from 1937. Govoruchin’s combination will have priority if it refers to the arctic plant in question. However, we have not come across any reference to a type for Hackel’s basionym (base name) f. arctica Hack. 1882. For the time being, we therefore go for the unambiguously typified name ‘richardsonii’.

Literature

Alsos, I.G., Müller, E. & Eidesen, P.B. 2013. Germinating seeds or bulbils in 87 of 113 tested Arctic species indicate potential for ex situ seed bank storage. – Polar Biology 36: 819–830. Doi 10.1007/s00300-013-1307-7.

Darbyshire, S.J. & Pavlick, L.E. 2007. Festuca L. – In: Flora of North America Editorial Committee (eds.), Flora of North America north of Mexico. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1: 389–443.

Elven, R., Murray, D.F., Razzhivin, V. & Yurtsev, B.A. (eds.) 2011. Annotated Checklist of the Panarctic Flora (PAF).

Eurola, S. 1972. Germination of seeds collected in Spitsbergen. – Annales Botanici Fennici 9: 149–159.

Markgraf-Dannenberg, I. 1980. Festuca L. – In: Tutin, T.G. et al. (eds.), Flora Europaea. 5. Alismataceae to Orchidaceae (Monocotyledones): 125–153.

Soreng, R.J., Peterson, P.M., Davidse, G., Judziewicz, E.J., Zuloaga, F.O., Filgueiras, T.S. & Morrone, O. 2003. Catalogue of New World grasses (Poaceae): IV. Subfamily Pooideae. – Contributions from the U.S. National Herbarium 48. 730 pp.