Taraxacum atomatum 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 : 67-69

8. Taraxacum atomatum Štěpánek & Kirschner , sp. nov.

Type:— Bulgaria meridionalis, montes Rodopi , opp. Čepelare , pars montium Černatica , pagus Chvojna , circum montem Goljam Persenk (2091 m), graminosis secundum viam turisticam lutee signatam in saltu inter montes Goljam Persenk (2091 m) et Persenk (2074 m), ca. 2 km supra (situ occidentali a) locum Skalni Mostove, ca. 1900–1950 m, ca. 41° 49’ N, 24° 33’ E, 24 Jul 1998, J. Štěpánek et al., cultivated as JŠ 6964, collected in 2000 ( PRA, no. det. 36092, holotype; isotype: PRA, no. det. 36094, and duplicates) .

Etymology:—Minutely spotted (from Latin atomus, particle), sprinkled with small particles.

Diagnosis:—Plantae insignes, foliis saturate viridibus, minute sparse maculatis, lobis lateralibus margine distali saepe denticulato, phyllariis involucralibus exterioribus basi arcte, superne laxe adpressis, obscure olivaceo-viridibus vel atroviridibus marginibus angustissimis, acheniis pallide brunneo-cinerascentibus, pallide griseo-fulvescentibus vel pallide ochraceo-griseis, corpore superne spinulis subdensis erectis vel squamulis tricuspidatis obsito, in pyramidem subcrassam, basi subconicam, ceterum subcylindricam subsensim transeunte.

Plants small, ± compact, 4–8 cm tall at anthesis. Plant base without tunic, with subdense light brownish-greyish hairs among petiole bases. Petiole broadly winged, 1–2 cm long, pale greenish at base, more distally light to deep purple. Leaves ± appressed to ground, deep green, sparsely minutely spotted brown-purple, glabrous to very sparsely arachnoid, oblanceolate to narrowly elliptical in outline, 3.5–8 × 1–3 cm, pinnatisect; terminal segment usually relatively large, broadly triangular to almost helmet-shaped, usually 0.8–1.6 × 1–2 cm, acute, sometimes shortly mucronate, distal margin, usually ± straight, sometimes subsigmoid, entire or with 1–3 little acute teeth, basal lobules patent to subrecurved, acute, relatively broad, proximal margin subconcave to ± straight, entire, rarely with a single tooth; lateral segments in 3–4 pairs, often ± patent, often subhamate-subrecurved, deltoid-triangular, narrowly triangular or birdwing-like, acute to acuminate, usually 5–15 mm long, 4–10 mm wide at base, distal margin convex to subsigmoid, entire or with 2–3 little teeth in outer leaves, more conspicuously and densely dentate or with 1–2 deeper incisions in inner leaves, proximal margin subconvex to subsigmoid, entire or with a single little basal tooth; interlobes short and ± narrow, usually 2–7 × 1.5–4 mm, almost entire in outer leaves, irregularly dentate with unequal narrow acuminate teeth in inner leaves, surface green or slighly suffused purplish, border not coloured, raised (including bases of segments); mid-vein pale greenish, sometimes faintly brownish. Scapes pale green, medium dense arachnoid, shorter than, or ± equalling the leaf length. Capitulum yellow, relatively large, 3–3.5 cm wide, flat to subconvex. Involucre not pruinose, 7–9 mm wide and rounded at base. Outer phyllaries 15–18, ± not imbricate, tightly appressed proximally, distally loosely appressed, ovate-lanceolate to lanceolate, usually 4.5–7 × 2.2–3 mm, reaching 1/3–2/5 of the inner, ± evenly dark greyish green to dark olivaceous-green, getting black when dry, with a ± abrupt transition in a dirty white border 0.05–0.1 mm wide, margin glabrous or distally minutely ciliate, apex darker, lingulate-elongated, obtuse, flat or ± carinate; inner phyllaries 10–11 mm long, of ± equal width. Outer ligules flat, striped purplish dark grey outside, apical teeth black or black-purple, inner ligules ± canaliculate, their apical teeth dark yellow or greyish. Stigmas light discoloured, greyish yellow-green, hairs of pubescence distally dark. Pollen abundant, pollen grains irregular in size. Achenes light greyish brown or light greyish beige to greyish-ochraceous, 3.9–5.0 × 0.9–1.1 mm, body with subdense erect to suberect spinules and often tricuspidate squamules in upper 1/4–1/5, ± subgradually narrowing into a basally subconical, otherwise ± subcylindrical cone 0.7–1.0 × 0.35–0.4 mm (measured including the uppermost, not coloured part of the cone; beak 5.5–6.5 mm long, pappus dirty white to slightly brownish white, 5–6 mm long. – Agamosperm. – Fig. 32D, 35.

Diagnostic notes:— Taraxacum atomatum seems to be a rather marginal member of T. sect. Bulgarica; in its leaf shape, achene colour and cone shape and length, it approaches T. sect. Rhodocarpa (= T. sect. Alpestria). It is, however, distinct in its minutely spotted leaves, the petiole coloration, and frequently dentate distal margin of leaf segments.

Distribution and habitat:— Taraxacum atomatum is restricted to the Rodopi Mts., S. Bulgaria, according to the material available. It grows in wet grasslands, at 1800–2000 m a.s.l. Its IUCN conservation status is estimated as VU.

Specimens examined:— BULGARIA. The Rodopi , Čepelare , the Černatica Mts. , Chvojna village , around Mt. Goljam Persenk (2091 m), 1.5–2 km W. of Skalni Mostove, 1800–1900 m, ca. 41° 49’ N, 24° 33–34’ E, 24 Jul 1998, J. Štěpánek et al., cultivated as JŠ 6926 ( PRA, no. det. 36096) .