Taraxacum oreades Štěpánek & Kirschner, 2022

Štěpánek, Jan & Kirschner, Jan, 2022, A hotspot of endemism: Oreophytic Taraxacum species (Compositae, Crepidinae) in the mountains of Bulgaria, Phytotaxa 569 (1), pp. 1-139 : 63

6. Taraxacum oreades Štěpánek & Kirschner , sp. nov.

Type:— Bulgaria, montes Rila , opp. Samokov , pagus Borovec , Musalenski Ezera, ad casam alpinam “Ledenoto Ezero” in ripa lacus VII. (= Ledenoto ezero) sub monte Musala (2925 m), ca. 2715 m, 9 Aug 1990, J. Štěpánek, cultivated as JŠ 4488, collected in 1991 ( PRA, no. det. 36086, holotype; isotype: PRA, no. det. 36088, and duplicates) .

Etymology:—Dwelling in the mountains (from Greek ορειαϛ, of the mountains).

Diagnosis:—Plantae ex affinitate T. bulgarici et T. circensi, differunt acheniis pallide brunneis vel pallide brunneo-cinerascentibus, crassis, ad 1.4 mm latis, corpore in pyramidem conicam, 0.5–0.8 mm longam, subabrupte transeunte, foliis glaberrimis, lobius lateralibus numerosis approximatis, stigmatibus obscuris, et phyllariis exterioribus adpressis, brevibus, obscure viridibus, in sicco atro-viridibus, marginibus angustis albo-membranaceis.

Plants small, compact, 6–11 cm tall. Plant base without tunic, with sparse brownish hairs among petiole bases. Petiole pale green, very broadly winged, 1–3 cm long. Leaf rosettes ± rich, ± appressed to the ground, leaves light green, not spotted, glabrous to subglabrous, mostly tightly appressed to the ground, some ± patent to erect-patent, narrowly oblong to narrowly elliptical in outline, usually 4–9 × 1.5–2 cm, usually pinnatifid to pinnatisect, sometimes pinnatilobed, with a small terminal segment and numerous, approximated lateral ones; terminal segment not very distinct, broadly triangular, usually 4–10 × 8–15 mm, subacute to obtusely acute, often with a short lingulate to triangular mucro, distal margin concave to ± straight, entire or with a tooth on one or both sides, basal lobules patent to pointing ± forwards, acute, proximal margin short, entire; lateral segments in 4–6 (7) pairs, approximated to almost overlapping, deltoidtriangular to narrowly so, usually 4–9 mm long, 5–12 mm wide at base, acute to obtusely acute, patent, or distal part curved upwards or downwards, distal margin convex to subconcave, entire or with one or several teeth of unequal length, proximal margin most often convex or ± straight, entire, seldom with a single tooth near the base; interlobes short and broad, usually 0–7 × 3–9 mm, green, not bordered, entire or with a few unequal teeth, the longest ones lobulelike; mid-vein usually pale, seldom faintly purplish. Scapes pale greenish at anthesis (later they may be suffused light purplish), initially sparsely long-arachnoid, later glabrescent, glabrous after anthesis, ± equalling the leaf length or slightly longer. Capitulum yellow, ca. 2.5 cm wide. Involucre not pruinose, usually 7–8 mm wide and rounded at base. Outer phyllaries 13–16, appressed, subimbricate, relatively short, reaching ca. 2/5 of the inner, ovate to lanceolate, usually (4.5–) 5–6 (–7) × 2.5–3 mm, ± evenly dark green (blackish when dry), with an abrupt transition in a whitishmembranous border 0.05–0.2 mm wide, margin minutely, irregularly ciliate, apex flat; inner phyllaries 10–11 mm long, of ± equal width. Outer ligules flat, striped purplish dark grey outside, apical teeth black to black-purple, inner ligules ± canaliculate, their apical teeth smoky grey. Stigmas dark discoloured, light grey-green to dirty yellow-green, with black pubescence outside. Pollen abundant, pollen grains irregular in size. Achenes thick, light brown to slightly greyish light brown, 4.2–4.9 × 1.2–1.4 mm, with subdense suberect short spinules and comb-like squamules in upper 1/6–1/8, subabruptly narrowing into a short, broad, conical cone 0.5–0.8 mm long, ca. 0.6 mm wide at base, ca. 0.4 mm distally; beak 4–6 mm long, pappus white, 5.5–6 mm long. – Agamosperm. – Fig. 32B, 33.

Diagnostic notes:— Taraxacum oreades is distinct in having numerous, conspicuously approximated lateral leaf segments, and the peculiar, light brown achene colour. It might be compared with T. circense that is different in much more slender, light beige achenes, and with T. bulgaricum (thin, deep grey to dark grey achenes, a very different leaf shape).

Distribution and habitat:—Known from several sites in the Mt. Musala area, the Rila, between 2500 and 2700 m. It grows on wet stony places along shores of alpine lakes. Its IUCN conservation status is estimated as VU.

Specimens examined:— BULGARIA. Rila , Samokov , Borovec , lakes of Muselanski ezera, E. foot of Mt. Aleko (2713 m), 2500–2600 m, 9 Aug 1990, J. Štěpánek, cultivated as JŠ 4281 ( PRA, no. det. 36090); probably also JŠ 4811 ( PRA, no. det. 36087). – Borovec, Musalenski ezera, near the chalet of Ledeneto Ezero, shore of lake VII, Ledeneto ezero below Mt. Musala, ca. 2715 m, 9 Aug 1990, J. Štěpánek ( PRA, no. det. 36085) .