Poa alpina L., Sp. Pl. 67. 1753 subsp. alpina

Ortega-Olivencia, Ana & Devesa, Juan A., 2018, Updated checklist of Poa in the Iberian Peninsula and Balearic Islands, PhytoKeys 103, pp. 27-60 : 27

17. Poa alpina L., Sp. Pl. 67. 1753 subsp. alpina

Poa alpina alpina Ill. Soreng and Peterson (2012: 11, fig. I, A-E), Pignatti (1981: 473).

Type.

"Habitat in alpibus Lapponicis, Helveticis" (lectotype designated by Soreng 2000, pg. 254: Herb. Linn. No. 87.2!).

Flowering.

June to August (September).

Ecology.

Pastures in pine forests, fir woods, beeches and bushes, ruderalised hills and rocky plains, on limestone, schist, granite and slate; 1200-3150 m a.s.l.

Distribution.

Circumboreal: Europe, Asia, N America, locally at low elevations in NW Africa (Morocco). N Spain, Cantabrian Mountains, Pyrenees and the Iberian System. And. Esp.: (Av) B Bi Ge Hu L Le Lo Na O P S (Sa) So Te Vi. For a representative list of studied materials, see Suppl. material 1.

Notes.

A characteristic of this species is the size and shape difference of the ligule on the basal leaves and shoots-especially the oldest ones-compared with that of the upper leaves. In the first case, the ligule is tiny, with a more or less complete margin; in the second case, the ligule is noticeably larger, often with an irregular margin and sometimes even split into two or more parts.

This is a very polymorphic taxon, with four recognised, sometimes intergrading varieties in the territory encompassed by our revision. Plant size, leaf stiffness and panicle contraction can vary extensively depending on altitude, exposure and soil type. The first of these varieties is Poa alpina var. Poa alpina [ Poa frigida Gaudin, Alpina 3: 33. 1808, type: "au-dessous du glacier de Plan-nové; dans la vallée de Bagnes etc."; P. alpina var. frigida (Gaudin) Salisb., Flora 16(2): 473. 1833; P. alpina var. genuina Godr. in Gren. & Godr., Fl. France 3: 543. 1855, nom. inval.; P. alpina var. involucrata Lange, Pugill. Pl. Hispan. 47. 1860, syn. nov., type: "In regione alpina Pyren. Hisp. ad Port de Benasque (9 Aug. c. fl.)!", lectotype designated here: "Herb. Joh. Lange (printed) / Poa alpina var. involucrata nob. / ligulio foliorum omnium truncatis, ver. / -illegible- infer. folio -illegible- tetta / Port de Benasque reg. alp. 9 Aug. 1851. (manuscr.)": C 10022547, specimen on the left), Fig. 5 ; P. nuriensis alpina Sennen, Bull. Soc. Bot. France 73: 677. 1926, nom. nud., syn. nov.; P. alpina subsp. digitata Beauverd, Bull. Soc. Bot. Genève, sér. 2, 26: 122, fig. 2a-g. 1936, type: "Hab. in locis apricis calidisque valleculae dictae "du Grand Tabuc" ad locum dictum "les Grangettes", ca. 1800 m alt., supra thermis "Le Monétier de Briançon”, 15 Julii 1933, leg. J. Vergnet et G. Beauverd"; P. badensis subsp. multiflora sensu Rivas. Mart., Itinera Geobot. 15: 705. 2002, non P. alpina var. multiflora Gaudin, Fl. Helv. 1: 245. 1828; P. nuriensis Sennen, Pl. Espagne n. 4063. 1916, nom. nud., in sched. (BC 70515; MA 11298), syn. nov.]. This circumboreal taxon includes large plants having large, generally delicate, non-rigid leaves with non-thickened margins-or thickened less than 0.05 mm-and developed inflorescences that are only slightly condensed. This variety is typically found in sheltered, less-exposed locations and is widespread throughout the range of the species [And. Spa.: (Av) B Bi Ge Hu L Le Lo Na O P S (Sa) So Te Vi].

Under more adverse conditions, the plants are usually small and possess short, stiff leaves with non-thickened, or up to 0.05 mm thick, margins and very contracted panicles. These plants have been designated as Poa alpina var. Poa brevifolia (Gaudin) Godr. in Gren. & Godr., Fl. France 3: 543. 1855 [ Poa alpina subsp. brevifolia Gaudin, Fl. Helv. 1: 245. 1828, basion., type: "in M. Sempronio ad pylas vallis Ganter"], a variety distributed in mountains of C Europe and extended through the central and eastern Pyrenees [And. Spa.: B Hu L]. This pattern of variation is probably clinal and needs to be checked experimentally. The third recognised variety, Poa alpina var. Poa molinerii (Balb.) Endl., Cat. Horti Vindob. 46. 1842 [ Poa molinerii Balb., Elenco 85. 1801, basion., type: "Locis saxosis, et siccis prope Tenda reperta est, ac in hortum Taurinensem adlata ab eximio Ignatio MOLINERI, cujus triviale nomen imposui, utpote ejus stirpis inventore"], comprises plants having leaves with whitish, cartilaginous, thickened (0.1-0.15 mm) margins that, together with the middle underside vein, form a clear, visible contrast to the green leaf blade, the latter mostly flat or conduplicate and rigid. This taxon, is distributed in mountains of S and C Europe and, to date, only two populations of P. alpina var. molinerii have been detected for Flora iberica, one in Andorra (Coll de Ordino, on the way to Casamanya, 2100 m; MA 514862) and the other in Spain ( Lérida, Clot del Munyidor, 2215 m; BC 877255).

Finally, Poa alpina var. Poa vivipara L., Sp. Pl. 67. 1753. [Type: "An haec α. β. sequentis tantum varietas"; Lectotype designated by Soreng 2000, pg. 254: three left-hand culms, LINN-87.4!; Poa vivipara (L.) Willd., Enum. Pl. 103. 1809; P. alpina subsp. vivipara (L.) Arcang., Comp. Fl. Ital. 785. 1882; P. alpina f. vivipara (L.) B. Boivin, Naturaliste Canad. 94: 628. 1967], includes plants with pseudoviviparous spikelets. This variety, distributed mainly in N and C Europe, Greenland, Iceland and N America, has only been detected in a population in the territory covered by Flora iberica (Spain: Na), namely, it was collected in the valley of Roncal at 1600 m a.s.l (SEV 97164). The inflorescences of these plants conserved on this sheet show a great contrast of colours: glumes and lemmas of light green and straight or curved, dark green proliferations.

Another taxon described for the flora of Morocco is Poa alpina subsp. stenobotrya Maire (Bull. Soc. Hist. Nat. Afrique N. 33: 95. 1942), which is distinguished by its linear-lanceolate panicle and the presence of hairs at the base of the lemmas.

Figures

Figure 5. Lectotype of Poa alpina var. involucrata Lange (C 10022547). Reproduced with permission of the Natural History Museum of Denmark.