Taraxacum mimosiflorum Kirschner & Štěpánek, 2025

Kirschner, Jan, Štěpánek, Jan & Buryy, Vladimir V., 2025, Towards a revision of Taraxacum sect. Borealia (Compositae, Crepidinae) in Siberia and the continental Far East, with special reference to the dandelions of the Altai and Kamchatka, Phytotaxa 679 (1), pp. 1-147 : 119

publication ID	https://doi.org/10.11646/phytotaxa.679.1.1
DOI	https://doi.org/10.5281/zenodo.16717188
persistent identifier	https://treatment.plazi.org/id/0399F353-FFE5-FFC0-FF78-FDA64A1AB45E
treatment provided by	Felipe
scientific name	Taraxacum mimosiflorum Kirschner & Štěpánek
status	sp. nov.

Treatment

51. Taraxacum mimosiflorum Kirschner & Štěpánek View in CoL , sp. nov.

Type:—[ RUSSIA, Altai Republic] USSR, Sibiria austro-occid., montes Altaj, pars Ajgulakskij chrebet, distr. Usť-Ulagan , in pratis haud procul a lac. Mjortvyje Ozera, ad clausam mont. Ulaganskij Pereval, ca. 1850–1900 m, 2 Jul 1988 , J. Kirschner , cultivated as T 180 ( PRA, no. det. 35853, holotype) .

Etymology:—The colour of flowers of Mimosa .

Diagnosis:—Plantae heterophyllae, tempore florendi foliis arachnoideis, aut indivisis aut dissectis, foliorum lobis patentibus, anguste vel late deltoidi-triangularibus, interlobiis maculatis, phyllariis exterioribus adpressis, non imbricatis, conspicue cornutis, pyramide subcylindrica longa et rostro conspicue elongato notabiles.

Plants medium-sized, ± robust, usually to 14 cm tall. Petiole most often faintly suffused pinkish brownish, sparsely arachnoid, usually broadly winged, outer petioles narrowly winged, plant base without tunic. Leaves ± mid-green to brownish mid-green, sparsely to subdensely, conspicuously arachnoid, later ± glabrescent, ± narrowly oblong in outline, usually 6–11 × (1.5–) 2.0–2.5 (–3.0) cm, leaf blade showing conspicuous heterophyly within each leaf rosette: (a) leaves undivided, ± remotely dentate, (b) leaves pinnatilobed to pinnatifid, usually with 5–6 pairs of patent, broadly deltoid-triangular to ± triangular lateral segments, mostly with distal margin straight to subconcave, denticulate (at least in proximal segments), proximal margin ± straight, entire, and (c) leaves deeply pinnatisect, with (3) 4–6 pairs of patent, linear-triangular or narrowly triangular acuminate segments with distal margin usually subconcave, entire, proximal margin ± straight, entire; in (c), interlobes well developed, medium broad, with 1–2 teeth or a single short linear lobule, interlobe surface often with brown-purple coloration; mid-vein brownish-purplish; terminal segment usually tripartite or trilobed, with acute to acuminate narrowly triangular lobules. Scapes brownish green, arachnoid, ± equalling leaves. Capitulum large, ca. 5 cm wide, light to medium yellow. Involucre dark olivaceous-green, usually 11–12 mm wide and broadly rounded at base. Outer phyllaries 11–15, appressed, ± not imbricate, ovate to ± narrowly ovate (or broadly lanceolate), (7.5–) 9–10 (–11) × (2.5–) 3.3–4.1 (–4.5) mm, middle strip blackish, 0.3–1.0 mm wide, with a gradual transition in a deep olivaceous-brown zone, again with a gradual transition into a paler green and submembranous border 0.3–0.6 mm wide, margin ± ciliate, apex (at least in later capitula) with blackish horns 1.2–2.5 mm long; inner phyllaries 13–15 mm long, not coalescing, conspicuously blackish corniculate. Outer ligules relatively narrow, ± flat to canaliculate, faintly striped light greyish outside, teeth yellowish grey, inner ligule teeth yellow. Stigmas greenish grey with dark grey pubescence outside. Pollen present, pollen grains irregular in size. Achenes light greyish stramineous-brown, 3.9–4.5 × 1.0– 1.3 mm, body subsparsely covered with ± robust medium-sized spinules to 0.2–0.3 mm long in upper 1/4–1/3, body subgradually (seldom subabruptly) narrowing into subcylindrical cone (0.8–) 1.0–1.1 (–1.2) mm long, usually ca. 0.4 mm thick at base, ca. 0.3 mm distally; beak thin, 11.5–13 mm long, pappus white, ca. 6 mm long. – Agamospermous. – Fig. 3G View FIGURE 3 , 82 View FIGURE 82 , 83 View FIGURE 83 .

Diagnostic notes:—The combination of the distinct heterophyly with at least some leaves pinnatisect and lateral segments patent, narrowly deltoid-triangular, the relatively long outer phyllaries with horns up to 2.5 mm long, the achenes with subsparse, relatively short but robust spinules, a subcylindrical cone over 1 mm long, and an unusually long beak (11.5–13 mm) is diagnostic. Moreover, leaves of T. mimosiflorum are more densely, conspicuously arachnoid in comparison with similar species.

Distribution:—Known from two sites in the Ulaganskiy Pereval region, Usť-Ulagan District, the Altai.

Specimens examined:—[ RUSSIA, Altai Republic] Usť-Ulagan District, range of Aigulakskii Khrebet, meadows in the vicinity of Myortvye Ozera ( Lakes ) near the pass Ulaganskiy Pereval , 1850–1900 m, 2 Jul 1988, J. Kirschner, cultivated as JŠ 3356 ( PRA, no. det. 36766). – Ibidem, cultivated as T 180 ( PRA, no. det. 36764, isotype). – Ibidem, cultivated as T 155 ( PRA, no. det. 36762) .