Mat-forming graminoid herb, early in the season with bunches of bushy, vegetative shoots with very narrow (filiform, closely convolute) leaves but soon setting stolons growing in a zig-zag pattern (changing direction at each node), up to 20−30 cm or sometimes more, with extravaginal branching at the nodes where the new branches break out through the base of the sheaths, a feature very rare (if known at all) in other northern grasses and absent from all other species of Puccinellia. If the branch seems to appear at the opening of a sheath, remove this leaf and see where it really comes from! Stolons root at the nodes, and in the autumn new bunches of bushy shoots are produced from these nodes. The stolon system usually forms a very open mat on the ground. The entire plant is reddish or purplish tinged, making the salt marshes where it grows appear brownish red in summer and autumn.

Culms (when present) 3−7 cm, erect, glabrous and smooth. Culms are produced only occasionally; most stands consist of vegetative shoots only. In mainland Norway, culms are produced under extraordinary conditions, e.g., when turfs are transported landwards by ice floes in the winter and deposited high on the shore (where soon overgrown by taller grasses, see Elven et al. 2013). This may be a panic reaction to unfavourable conditions. In Svalbard, culms are found more often and also within ordinary salt marshes.

Leaves 1−3 cm, rarely more than 1 cm on stolons, usually folded (or filiform on bushy shoots), indistinctly keeled and with apex like the prow of a boat, with veins on the upper surface broad and raised, on the lower surface narrow and less raised, smooth and glabrous. Ligula 0.5−1.2 mm, acute or obtuse, usually entire.

Anatomical details in leaf surface where applied by Sørensen (1953) to distinguish races but these demand a high-power microscope and special preparation techniques. They are omitted here but commented on below.

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). Stamens 3.

Inflorescence a contracted or more or less open panicle, up to 2.5 × 2 cm, occupying 1/2−1/3 of culm length. Panicle with 4−6 nodes with 1−2 branches at each of the lower nodes, violet or purple in colour throughout (branches, pedicels and spikelets). Branches erect, erectopatent or rarely patent, 5−10 mm, smooth, each with 1−2 spikelets in the distal part. Spikelets 3−4 × 1.7−2.0 mm, with (1)2−3(4) flowers. Bracts (glumes and lemmas) with rounded backs. Glumes unequal, both much shorter than the lemmas, smooth and glabrous, with distinct, green veins, violet throughout or with a white hyaline tip; lower glume ca. 2 × 1.2 mm, ovate or oblong, obtuse or subacute, with 1 vein; upper glume ca. 3 × 1.8 mm, oblong, subacute or acute, with 3 veins. Lemmas 2.6−3.0 × 1.0−1.4 mm, oblong or ovate, subacute, with a more or less even apex (not lacerate, not ciliolate), with 5 distinct rib-like yellowish or green veins, smooth and glabrous, violet with a very narrow yellowish and/or white hyaline margin. Paleas as long as lemmas, with glabrous and smooth veins (keels). Anthers always shrivelled and non-functional, ca. 1.5 mm long.

No fruit set observed in Svalbard, and none assumed.

Vegetative reproduction by detached branches and stolons. Stolons and especially branches from the stolons are very brittle, breaking off at the gentlest touch and easily floating away. No seed reproduction in Svalbard plants (but see Comments).

Shoot fragments (stolons, branches) are dispersed by sea currents and very probably also by birds.

The species of Puccinellia can be mistaken for Poa but differ in having no keel on glumes or lemmas but rather an evenly rounded back. They also differ in lemmas broad nearly to the apex, often truncate, rounded or subacute with apex uneven, lacerate or fringed, whereas all Poa have lemmas tapering gradually towards a usually acute apex and usually entire in the margin (however, the lemmas of Poa abbreviata, P. glauca and P. hartzii may have lacerate apices).

The genus Puccinellia is notoriously difficult and with numerous species in the Arctic, many of them endemic (restricted) to the arctic regions. They are difficult also in Svalbard. We here recognize five species but there may be more (especially in the affinity of P. angustata).

Puccinellia phryganodes differs from all the others in being stoloniferous (with above-ground runners) and asexual with aborting flowers (look for shrivelled anthers) and little flowering; all the others are tussocky, sexual and always abundantly flowering. The stolons of P. phryganodes are unmistakeable among arctic grasses. They are extended, zig-zag-formed, and numerous branches break out through the bases of the leaf sheaths in a very typical way. The only similar plant in the Norwegian flora is P. maritima (Huds.) Parl., a more southern species that reaches the Arctic in N Norway and in southernmost Greenland. It differs by having sexual seed reproduction and especially in the branching of the stolons being intravaginal, i.e., new shoots emerging inside the sheaths, coming out at their opening where the blade is attached.

Puccinellia angustata and P. vahliana both have paleas with intertwined hairs on the proximal (lower) parts of the keels (veins), whereas P. coarctata and P. svalbardensis have no intertwined hairs on palea keels. Puccinellia vahliana differs most distinctly from P. angustata in the glumes. In P. vahliana they are mostly subequal, the longest about the same length as the lower lemmas, and firm; in P. angustata they are unequal, both much shorter than the lower lemmas, and flimsy.

Puccinellia svalbardensis differs from (arctic) P. coarctata most distinctly in the shape of the panicle. The panicle of P. svalbardensis is very open with long, very slender, spreading, patent or even retrorse branches; that of P. coarctata is more contracted with stouter, erect or erectopatent branches. The keels (veins) of the paleas in P. svalbardensis are smooth, those of P. corarctata scabrous at least in their distal (upper) parts. In addition, the lemmas of P. svalbardensis are lacerate, whereas those of P. coarctata are distinctly ciliolate (with one-celled teeth). Mistaking these two species is, however, impossible in practice in Svalbard as P. coarctata is a seashore species restricted to Bjørnøya, whereas P. svalbardensis mainly is an arctic steppe species and restricted to northern parts of Spitsbergen.

In all zones and sections.

Puccinellia phryganodes is recorded from all the four major islands and from Bjørnøya, the northern tip of Prins Karls Forland, and Svenskøya in Kong Karls Land. It is almost exclusively a salt marsh species (but see Adventdalen in the map), and the absence from Hopen may be due to absence of any salt marsh habitat whatsoever. The species is frequent along the shores of Spitsbergen north to the offshore island of Moffen, and in Nordaustlandet, probably also in western Edgeøya.

Puccinellia phryganodes s. lat. is common in the circumpolar areas, both in the arctic zones and in the northern boreal ones, in Europe south to Finnmark in N Norway (and previously also the Bothnian Bay in Finland). Several races have been reported, see Comments.

Four rather different sections of Puccinellia are present in the Arctic, three of these in Svalbard: the stoloniferous sect. Paralochloa to which P. phryganodes belongs, sect. Pseudocolpodium to which P. vahliana belongs, and sect. Puccinellia to which all the other species belong. In a Svalbard context, P. phryganodes is very different from the other species of the genus in several aspects, both morphologically and ecologically. It is a complicated and very interesting species in a circumpolar context.

Sørensen (1953) identified morphological differences in inflorescence and microscopic ones in leaf epidermis among four races with different geographic patterns within P. phryganodes. He treated the races informally as ‘Beringian’, ‘Greenland’, ‘Fennoscandian’, and ‘Spitsbergen types’, but he stated that: "If any nomenclatorial consequences were to be drawn from the present investigation, it would be to ascribe subspecific rank to each and all of the four distinguished types." Löve & Löve (1976) raised those of Sørensen's ‘types’ that differed in ploidy level to rank of species within Phippsia, the diploid as Phippsia phryganodes (but probably erroneously), the triploid as Phippsia neoarctica, and the tetraploid as Phippsia vilfoidea. Sørensen's ‘types’ are similar in macromorphology and without any identified diploid relatives (perhaps except for the Beringian P. geniculata (V.I.Krecz.) T.J.Sørensen. Taxonomic autopolyploidy is therefore suspected. They are allopatric or parapatric, replace each other around the Polar Sea, and we provisionally have accepted them as subspecies as proposed by Sørensen (e.g., Elven & Murray 2008; Elven et al. 2011). Davis & Consaul (2007) did not accept races and did not comment on the morphological variation or on sexuality vs. vegetative spread. There is therefore little information to get from the otherwise often informative treatments for the Flora of North America.

We have inspected the type of Poa phryganodes in the Komarov herbarium (LE) in St. Petersburg, from "Kotzebue-Sund" in the Bering Straits area in West Alaska, and much material in the field around "Kotzebue-Sund", and we are sure that Trinius' Poa phryganodes is a probably tetraploid plant from this area (as opposed to Löve's diploid plant from much farther south). It is most probably sexual as it flowers regularly, with good anther development and pollen production, and good seed-set (but see Tzvelev 1976: 496). We also assume that the W Alaskan tetraploid chromosome count of Johnson & Packer (1968) belongs to this narrowly Beringian race and that this most probably corresponds to Sørensen’s ‘Beringian type’.

All plants of P. phryganodes from outside the Bering Straits region seem to be seed-sterile and to reproduce only vegetatively by stolons and detached branches. These plants were assigned by Sørensen, and later by Löve & Löve, to three races or species: the western arctic ssp. neoarctica (Á.Löve & D.Löve) Elven (Phippsia neoarctica Á.Löve & D.Löve, Sørensen’s ‘Greenland type’), the eastern arctic ssp. sibirica (Hadač & Á.Löve) Elven (Sørensen’s ‘Fennoscandian type’), and the restricted Svalbard and Novaya Zemlya endemic ssp. vilfoidea (Andersson) Tzvelev (Phippsia vilfoidea (Andersson) Á.Löve & D.Löve; Sørensen’s ‘Spitsbergen type’). Subspecies neoarctica has been considered to be triploid (2n = 21), whereas both ssp. sibirica and ssp. vilfoidea have been considered to be tetraploid (2n = 28). However, the plants of assumedly ssp. sibirica in N Norway are mainly triploid (rarely hexaploid), whereas those in Russia assigned to the same subspecies are consistently tetraploid (see Elven et al. 2011). Several ploidy levels have been identified in Svalbard plants (Føreid 2012). The correlations between ploidy levels and geographical ranges are therefore much less clear-cut than previously assumed.

Three of Sørensen’s types are then present in the areas surrounding the North Atlantic, and two of them have been reported from Svalbard. In addition to the common ssp. vilfoidea (the ‘Spitsbergen type’), Sørensen (1953) identified a collection from Biscayerhuken on the north coast of Spitsbergen (Haakon VII Land) as belonging to the ‘Greenland type’ (i.e., ssp. neoarctica), based on leaf epidermis and floral features, with the following comment on the herbarium label in 1952: "Dette exemplar (collection!) kan jeg ikke skelne fra de grønlandske og forbigaar det helst i stilhed. En etikettsforbytning er vel udelukket? Epidermis vortet." [This specimen (collection) I am unable to distinguish from the Greenland ones and I prefer to not comment on it. A mixture of labels is probably impossible? Epidermis papillose.] A mislabelling is, indeed, impossible as concerns this collection, and plants with similar characters have been found in at least two other localities, at Velkomstpynten (also on the north coast of Spitsbergen in Haakon VII Land) and at Bohemanneset (by Isfjorden, Oscar II Land), and suggested by Sørensen himself in annotations on a label on a collection from the Longyearbyen area. We are not convinced that only one ‘type’ of P. phryganodes is present in Svalbard and therefore here refer Sørensen’s diagnostic characters for the future use of interested collectors:

Characters diagnostic for ssp. vilfoidea (the ‘Spitsbergen type’) vs. the two others: In ssp. vilfoidea pedicels thickened, spikelets 2–6-flowered, glumes firm and concave, second glume 1.5–2.0 mm with distinct main vein and two obscure lateral veins, lemmas 2.5–3.0 mm, keels of palea smooth, and epidermis of leaves of vegetative shoots and runners smooth and without tumid cells; in the two others pedicels not or scarcely thickened, spikelets 2–6-flowered, glumes flimsy and more or less flattened, second glume 2–3 mm and with 3 distinct veins, lemmas 3–4 mm, keels of palea papillose, and epidermis of leaves of vegetative shoots and runners strongly papillose and/or with tumid cells. The study of the epidermis needs a special technique. Sørensen and others have used nail polish, put on the leaf surface in a medium thick layer and then removed and studied under a strong microscope, preferentially with some oblique light. The features are well illustrated in Sørensen (1953).

For separation between ssp. neoarctica (the ‘Greenland type’) and ssp. sibirica (the ‘Fennoscandian type’), the following characters are used: In ssp. neoarctica spikelets 3–4-flowered, lemmas oblong or obovate with obtuse or slightly emarginate apex, with a broad hyaline margin and a mid vein ending in the hyaline margin or in the notch in an emarginate apex, and leaf epidermis with 2 or less grooves of bulliform cells and ridges smooth or very indistinctly spinulose; in ssp. sibirica spikelets 2–4-flowered, lemmas tapering and acute or subacute in apex, with a narrow white hyaline margin and a mid vein running into the very apex, and leaf epidermis with more than two grooves of bulliform cells making the surface ridged and with spinulose ridges.

The morphological variation in the Svalbard Puccinellia phryganodes needs a new investigation. Also the variation in ploidy levels found by Føreid (2012) throws some doubts on whether the Svalbard population is uniform, and on whether there is any strict connection between ploidy levels and morphological races even in Svalbard. For Svalbard, we have therefore decided to enter the species only, without accepting subspecies until the complex is further studied. This conclusion is based to a large degree on the results of Føreid (2012).

Davis, J.I. & Consaul, L.L. 2007. Puccinellia Parl. – In: Flora of North America Editorial Committee (eds.), Flora of North America north of Mexico. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1: 459–477.

Elven, R., Fremstad, E. & Pedersen, O. (eds.) 2013. Distribution maps of Norwegian vascular plants. IV The eastern and northeastern elements. − Akademika Publishing, Trondheim.

Elven, R. & Murray, D.F. 2008. New combinations in the Panarctic vascular plant flora. – Journal of the Botanical Research Institute of Texas 2: 433–446.

Elven, R., Murray, D.F., Razzhivin, V. & Yurtsev, B.A. (eds.) 2011. Annotated Checklist of the Panarctic Flora (PAF) Vascular plants. http://panarcticflora.org/

Føreid, M.K. 2012. Migration history and migration potential of Puccinellia phryganodes. − M. Sc. Thesis, UNIS, Longyearbyen & Univ. Tromsø, Tromsø.

Johnson, A.W. & Packer, J.G. 1968. Chromosome numbers in the flora of Ogotoruk Creek, N.W. Alaska. – Botaniska Notiser 121: 403–456.

Löve, Á. & Löve, D. 1976. Nomenclatural notes on arctic plants. – Botaniska Notiser 128: 497–523.

Sørensen, T.W. 1953. A revision of the Greenland species of Puccinellia Parl. – Meddelelser om Grønland 136(3). 179 pp.

Tzvelev, N.N. 1976 [1977]. Zlaki SSSR. – Nauka, Leningrad.