A hotspot of endemism: Oreophytic Taraxacum species (Compositae, Crepidinae) in the mountains of Bulgaria Author Štěpánek, Jan 0000-0003-4038-1998 Institute of Botany of the Czech Academy of Sciences, CZ- 25243 Průhonice 1, Czech Republic. & jan. stepanek @ ibot. cas. cz; https: // orcid. org / 0000 - 0003 - 4038 - 1998 jan.stepanek@ibot.cas.cz Author Kirschner, Jan 0000-0002-6303-713X Institute of Botany of the Czech Academy of Sciences, CZ- 25243 Průhonice 1, Czech Republic. & jan. kirschner @ ibot. cas. cz; https: // orcid. org / 0000 - 0002 - 6303 - 713 X jan.kirschner@ibot.cas.cz text Phytotaxa 2022 2022-10-20 569 1 1 139 http://dx.doi.org/10.11646/phytotaxa.569.1.1 journal article 172051 10.11646/phytotaxa.569.1.1 f8f7b3a8-119f-438c-95d6-5d701a007727 1179-3163 7235182 . Taraxacum musalae Štěpánek & Kirschner , sp. nov. Type :— Bulgaria , montes Rila , opp. Samokov , pagus Borovec , secus viam inter casas alpinas Jastrabec et Musala , 2200–2350 m , 9 Aug 1990 , J . Štěpánek & B . Kuzmanov , cultivated as JŠ 4507, collected in 1991 ( PRA , no. det. 35740, holotype ; isotype: PRA , no. det. 25479, and duplicates) . Etymology :—Derived from the name of the highest summit in the Rila, Mt. Musala. Diagnosis :—Plantae a speciebus ceteris sectionis Bulgaricorum foliis prostratis vel patentibus, conspicue subdense maculatis, acheniis saturate obscure griseis vel obscure griseo-brunneis, corpore superne spinulis latis et squamulis brevissimis suberectis vel erectopatentibus obsito, in pyramidem conicam, 0.5–0.8 mm longam subabrupte abeunte, et phyllariis exterioribus late marginatis bene dignoscendae. FIGURE 4. Taraxacum chionogeiton (PRA, no. det. 36149, holotype). Photo M. Hladík. Plants light green, small, 6–12 cm tall. Plant base without tunic, with sparse hairs among petiole bases. Petiole pale to pale greenish, very broadly winged in outer leaves, winged to narrowly winged in inner leaves, usually 1.5–3.5 cm long. Leaf rosette ± compact, leaves prostrate to patent, light green to yellowish green, conspicuously and ± densely spotted adaxially, ± glabrous, narrowly oblanceolate to narrowly oblong or narrowly elliptical in outline, usually 5–10 × (1–) 2–2.5 cm , pinnatisect to pinnatipartite, with approximated segments; terminal segment small, flat triangular to ± flat rhombic, sometimes trilobed or mucronate, usually 5–11 × 8–15 mm , acute to obtusely acute, distal margin convex to sigmoid, usually entire, basal lobules patent, acute, proximal margin subconcave to straight, entire; lateral segments in 4–5 pairs, patent to recurved, deltoid-triangular, hamate-triangular or bird-wing-like with a narrow distal part, ± densely spotted, usually 5–10 mm long, 4–7 mm wide at base, acute to acuminate, distal margin convex to subsigmoid, usually with 2 (3) teeth, proximal margin ± straight to subconcave, usually entire; interlobes short and ± broad, usually 1–5 × 3–5 mm , light green and adaxially spotted, not bordered, margin usually raised, entire or with 1–2 small teeth or a single bigger tooth; mid-vein pale green, often slightly suffused brownish. Scapes pale greenish, very sparsely arachnoid or glabrescent, equalling or ± overtopping the leaf length. Capitulum yellow, 2.5–3 cm wide, ± flat. Involucre not pruinose, usually 7–9 mm wide and rounded to broadly obconical at base. Outer phyllaries 15–19, loosely appressed, ± imbricate, lanceolate to broadly lanceolate, short, reaching 1/3–1/2 of inner phyllaries, usually 4–6.5 × (1.5–) 2–3 mm , surface ± evenly dark olivaceous-green (± black when dry), with a subgradual to ± abrupt transition in a distinct whitish to whitish-membranous border 0.2–0.5 mm wide, margin glabrous or sparsely minutely ciliate, apex flat; inner phyllaries 11–12 mm long, of ± equal width. Outer ligules flat, striped grey-green, sometimes purplish grey-green outside, apical teeth black-purple, inner ligules canaliculate, their apical teeth dark yellow to reddish. Stigmas long, light to medium discoloured, greyish light green, hairs with apical part dark. Pollen abundant, pollen grains irregular in size. Achenes deep brown-grey to deep grey, rarely lighter brown, 3.5–4.5 × 1.1–1.2 mm , body with subdense, very short, suberect to erect-patent squamules and broad spinules in upper 1/3–1/6, subabruptly narrowing into a conical cone 0.5–0.8 mm long, ca. 0.4 mm thick at base, 0.25–0.3 mm distally, often clearly paler than achene body; beak (2–) 4–6 mm long, pappus pure white, 5–5.5 mm long. – Agamosperm. – Fig. 37D, 43, 44. Diagnostic notes :—At first sight, T. musalae is distinct in its spotted leaves, distinct, relatively broad border to outer phyllaries, and the dark achene colour. In its general habit, it approaches T. saevum (differences are summarized under the latter species). Distribution and habitat :—Known from several localities in the Mt. Musala Massif, Rila, and is considered as endemic to that area, at the elevations between 2100–2400 m . It grows in subsparse short alpine grasslands, often on slightly disturbed sites, such as along tourist paths and in the vicinity of alpine chalets. Its IUCN conservation status is estimated as VU. FIGURE 4. Taraxacum musalae . General habit (PRA, no. det. 25481). Scale bar = 2 cm. FIGURE 44. Taraxacum musalae (PRA, no. det. 35740, holotype). Photo M. Hladík. Specimens examined :— BULGARIA . The Rila , Borovec , semiruderal places near the alpine chalet of Musala , ca. 2390 m , 9 Aug 1990 , J . Štěpánek & B . Kuzmanov ( PRA , no. det. 25483); Ibidem , cultivated as JŠ 4511 ( PRA , no. det. 25480). – Borovec, along a track between alpine chalets of Jastrebec and Musala, 220–2350 m , 9 Aug 1990 , J . Štěpánek & B . Kuzmanov ( PRA , no. det. 25482); Ibidem , cultivated as JŠ 4507 ( PRA , no. det. 25479). – Borovec, wet places in the valley of Bistrica, ca. 1–2 km below the Musala Chalet, ca. 2100 m , 9 Aug 1990 , J . Štěpánek , cultivated as JŠ 4814 ( PRA , no. det. 25481). – Borovec, below the summit of Mt. Musala , ca. 2150 m , 11 Jul 1988 , J . Štěpánková , cultivated as JŠ 4462 ( PRA , no. det. 25478); Ibidem , JŠ 3455 ( PRA , no. det. 25477); Ibidem , JŠ 4460 ( PRA , no. det. 25476); Ibidem , JŠ 3453 ( PRA , no. det. 25475) .