Poa (Alpinae) (sect. Alpinae) (ser. Alpinae) Roshev.

Poa subg. Alpinae sect. Alpinae ser. Alpinae Roshev. Description. Perennials; hermaphroditic; tufts small, dense; tillers intravaginal; old sheaths persisting and forming tunics; bulbs absent. Culms 5–40 (– 70) cm tall. Basal leaf - blades usually 1–3 mm wide, moderately thick, and holding their form in age (sometimes with sclerified thickened margins) (Jirásek 1935 b; Buschmann 1942). Panicles short, open or contracted; branches smooth or sparsely to moderately scabrous. Spikelets rarely bulbiferous (except in P. alpina var. vivipara L.); lemmas variously pubescent; lemmas with intermediate veins faint or distinct. Flowers perfect (bulbiferous in P. alpina var. vivipara); anthers 1–2 mm long; Clade code: Aa. Species included. Poa alpina, P. badensis (syn., P. crassipes Domin ex Sourek), P. bivonae Guss. P. djurjurae Batt. & Trab., P. lavrenkoi Kuczerov, P. magellensis F. Conti & Bartolucci, P. molinerii [now P. badensis subsp. molinerii (Balb.) Duck. - Henr. & Favarger ex Soreng], P. ophiolithica H. Scholz, P. parnassica, P. pumila, P. thessala (syn., P. alpina subsp. falax F. Herm., P. bussmannii, P. imeretica?). Distribution and ecology. Plants occur mostly in rocky habitats in upland steppe, subalpine, and alpine regions, extending to the Arctic (Poa alpina). Native to western Eurasia and northwestern Africa, the species range from high steppe and boreal forest openings to alpine habitats, often as calciphiles. Poa alpina has spread across the Northern Hemisphere in alpine to arctic tundra (but is infrequent in Far East Asia), sporadically extending into boreal forests, as far south as New Mexico in North America (Soreng and Peterson 2012). Poa alpina s. s. is scattered across Turkey, reaching the Taurus Mts. Poa thessala is common in the alpine regions of Turkey. The molecular data suggest that “ P. badensis ” in the east (Caucasus and south) is separate from P. badensis in western Europe and belongs to P. thessala. For a discussion and map of P. badensis s. l. as a ring species, see Buschmann (1942). According to Tzvelev and Probatova (2019) P. imeretica has narrower and softer blades than Caucasian P. badensis (our P. thessala). Comments. IE nrDNA genotypes of Poa alpina were identical from around the Northern Hemisphere (Fig. 2) and resolved on a long and strongly supported branch within the A-clade. However, its plastid sequences showed mixed patterns (Fig. 1). One Canadian Arctic sample resolved with P. badensis from Austria and Slovakia. In Turkey, another sample, P. alpina sample (Soreng et al. 8976), resolved with some P. thessala samples but showed no intermediacy, whereas Soreng et al. 8975 was intermediate in morphology between P. alpina and P. thessala. Compared to the other non-bulbous species included here for the section, P. alpina has relatively tender leaf blades, with well-spaced veins, and little sclerenchyma thickening in the margins, in addition to lower shoot ligules shorter than their blade widths. The other species exhibit firmer, often rigid blades, crowded veins, distinctly thick margins, and lower shoot ligules usually longer than the blade width. The taxonomy of the bulbless species of subg. Alpinae needs further work, and several taxa lack DNA data or are poorly known. Poa badensis samples from central Europe grouped together in the IE tree (Fig. 2), but samples initially treated as that species from the Caucasus aligned with our P. thessala from Turkey and Greece, apart from Soreng et al. 8020 from the Caucasus Mts., and are here tentatively treated as P. thessala. This is a new taxonomic interpretation. It is uncertain whether this is the best way to treat the Caucasus material, which is usually treated as P. badensis. Anatomically, P. alpina and P. badensis differ in leaf cross section (Jirásek 1935 b; Buschmann 1942). All P. badensis and P. thessala have semirigid blades with thickened, indurate margins and with tightly packed veins, but lower ligules vary from shorter to longer than the blade width. It remains uncertain how to separate these two taxa. In contrast, P. alpina has soft blades with scarcely thickened margins and well-separated veins, and the ligules of lower leaves are shorter than the blade width. Furthermore, there is a western set of P. thessala in Turkey and Greece evident in MRT (Fig. 1). However, all the Turkish and Caucasus samples are united in IE (Fig. 2). None of these samples align with P. badensis from Europe (Caucasus region excluded). Poa parnassica and P. thessala were sampled from Type localities in Greece, but these names have been confused and inconsistently applied in the literature (Buschmann 1942; Nygren 1962; Edmondson 1980, 1985; Scholz 1986; Strid 2016 a, 2016 b), particularly with P. pumila s. s., a name we remain unsure how to apply, but which was rejected for Greece by Scholz (1986). Poa bussmannii, named from Kayseri Province, Turkey (by Scholz in Greuter and Raus 2010), corresponds to small plants of P. thessala as are found in populations of variable stature from other sites, and we do not accept it as a separate taxon (see population sample photos: TURKEY herbaria / NKU _ tk 2014 / rjs DSC _ 2395. jpg). Its shorter stature presumably resulted from selection under centuries of heavy grazing pressure there. Two collections sampled here (Hajkova 2004- 12 from Bulgaria, and Soreng et al. 7522-1 from the Type locality in Greece) agree with P. parnassica (with callus hairs, but unlike P. pumila Host (sensu Edmondson 1980), with hairs across the lemma surfaces). Poa thessala, and P. badensis (usually), do not have callus hairs. Distribution and ecology. Poa alpina occurs in Turkey (Artvin, Erzurum, Giresun, Rize, Trabzon), on alpine slopes, on sedimentary substrates, 2,040–2,950 m. Poa thessala occurs in Turkey (Afyonkarahisar, Ağrı, Amasya, Antalya, Bayburt, Bursa, Erzurum, Giresun, Gümüşhane, Isparta, Kayseri, Niğde, Rize), on alpine slopes, on igneous and sedimentary substrates, 2,100–3,350 m.