Taraxacum musteum Stepanek & Kirschner 2022, sp. nov.
Creators: name: Štěpánek, Jan
name: Kirschner, Jan
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Asterales
Asteraceae
Taraxacum
Taraxacum musteum

description: 9. Taraxacum musteum Štěpánek & Kirschner, sp. nov.   
 Type:— Bulgaria, urbs Sofia, montes Vitoša, pagus Dragalevci, graminosis herbosisque secundum viam turisticam in loco Meča poljana situ meridio-orientali a deversorio Aleko, in declivitate boreo-orientali montis Malak Rezen (2191 m), ca. 1850–1950 m, ca. 42° 34’ N, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6905, collected in 2000 (PRA, no. det. 35757, holotype; isotype: PRA, no. det. 25435, and duplicates).   
 Etymology:—Fresh, young, vivid (from Latin, musteus).   
 Exsiccates:— Taraxaca Exs., no. 1298–1307.   
  Diagnosis:—Species bulgarica divulgata, petiolis pallide viridibus, foliis pallide viridibus vel lutescenti-viridibus, ± glabris, nitentibus, scapis glabris, phyllariis involucralibus exterioribus laxe adpressis vel erectis, angustis, 1.5–2 mm latis, angustissime inconspicue marginatis, acheniis pallide stramineo-brunnescentibus vel pallide stramineo-fulvescentibus, corpore superne dense breviter spinuloso-squamuloso, in pyramidem cylindricam vel subcylindricam, 0.8–1.3 mm longam subsensim transeunte, bene dignoscendae.    
Plants medium-sized, less often small, usually 6–15 cm tall. Plant base without tunic, with very sparse hairs among petiole bases. Petiole light greenish, ± unwinged or narrowly winged in young, inner leaves, broadly winged, 1.5–3 × 1–2 cm, in outer leaves. Leaf rosette ± compact, leaves variously erect-patent, patent or prostrate, light vivid green to yellowish green, almost totally glabrous (occasional hairs along mid-vein), shining, not spotted, three-dimensional with raised to plicate interlobe margins, narrowly elliptical to oblanceolate, usually 4.5–10 × 1.5–3.5 cm, pinnatisect; older, outer leaves yellowish green; terminal segment broadly triangular to flat rhombic, 1–2 × 1.5–3.5 cm, often ± trilobed, distal margin concave, entire or undulate, proximal margin ± straight, entire, basal lobules patent, ± acute; lateral segments in 2–3 (4) pairs, hamate-recurved, usually 0.7–1.5 cm long, 0.7–1.4 cm wide at base, distal margin convex to ± straight and undulate, ± entire, proximal margin distinctly concave, ± entire; interlobes relatively broad, 2– 9 × 3–8 mm, green, not bordered, entire, margin raised, often plicate, rarely with 1–2 teeth; inner leaves differ in darker colour, terminal segment triangular, (2–) 2.5–3.5 × (2–) 3.5–4.5 cm, often with a sagittate base, lateral segments in 3–5 pairs, narrowly triangular, ± conspicuously recurved, distal margin subsigmoid to ± convex, undulate, entire or with a few little teeth, proximal margin ± straight to subconcave; mid-vein pale greenish. Scapes pale greenish, ± glabrous, shorter than leaves. Capitulum deep yellow, ca. 3.5 cm wide, ± flat to subconcave. Involucre light green, pruinose, subobconical to ± rounded and 7–8 mm wide at base. Outer phyllaries 13–19, ± loosely appressed to erect, lanceolate to narrowly lanceolate, relatively small, 4–6 × 1.5–2 mm, reaching 2/5–1/2 of the inner ones, light to medium dark olivaceous-green, with a darker base, middle line and apex, with ± abrupt transition in a whitish-membranous or greyish border 0.05–0.1 mm wide, margin sometimes minutely ciliate in distal 1/4, apex often reddish, subcallose; inner phyllaries 12–13 mm long, light green, of unequal width (not coalescing). Outer ligules relatively long, flat, striped purplish grey-olivaceous outside, apical teeth black-purple, inner ligules canaliculate, their apical teeth dark yellow to dirty yellow. Stigmas discoloured, yellow-green with a medium dark pubescence outside. Pollen present, pollen grains irregular in size. Achenes light stramineous-brown, often with a light greyish or light beige hue, 4.0–5.3 × 0.9–1.0 mm, body with distinct lateral ridges, ± densely covered with short spinules and squamules, spinules on ridges more robust, body subgradually narrowing into a cylindrical to subcylindrical cone 0.8–1.3 × ca. 0.3–0.35 mm, with a few minute spinules proximally; beak (4.5–) 5.5–6.5 mm, pappus white or whitish, 5.5–6.5 mm long. – Agamosperm. – Fig. 55, 56, 60A.  
 Diagnostic notes:— Taraxacum musteum, a member of the T. alpestre group, is also similar to the group of species around T. chrysocephalum. It is distinct in having yellowish green leaves, ± glabrous scape, pale greenish petiole and mid-vein, light green and pruinose involucre, outer phyllaries loosely appressed to erect, relatively light green and inconspicuously bordered, achenes light stramineous-brown, with distinct lateral ridges, ± dense spinulosity and short but robust spinules on ridges, and a relatively narrow and long cone. It is similar to T. carpaticum that is sexual and has pollen grains of regular size, outer phyllaries unbordered, mid-vein often purplish, and cone shorter and conical.   
 Distribution and habitat:— Taraxacum musteum is one of the most widely distributed mountain species in Bulgaria. It was recorded from the Stara Planina, the Vitosha, Rila, Pirin and Rhodopes. It grows in wet grasslands along brook in the subalpine and alpine belts, at an elevation of 1750–2550 m. Its IUCN conservation status is estimated asLC.   
 Specimens examined:— BULGARIA. Pirin, Bansko, Banderica valley, upper part of the valley of Vichrenska voda brook, below the Vichrenski Preslap ridge, ca. 2450 m, 12 Aug 1990, J. Štěpánek, cultivated as JŠ 4540 (PRA, no. det. 25440). – Bansko, valley of Banderica, valley of Vichrenska voda [brook], above the Vichren Chalet, ca. 2300 m, 12 Aug 1990, J. Štěpánek, cultivated as JŠ 4537 (PRA, no. det. 26189). – Bansko, valley of Banderica, below the pass of Vichrenski preslap between Mt. Chvojnati vrch and Mt. Vichren, ca. 2450–2550 m, 41° 45–46’ N, 23° 24–25’ E, 9 Aug 1997, J. Štěpánek, J. Kirschner & B. Trávníček, cultivated as JŠ 6508 (PRA, no. det. 25438); Ibidem, JŠ 6509 (PRA, no. det. 25432); Ibidem, JŠ 6549 (PRA, no. det. 25429). – Banderica, Mt. Vichren slopes, 9 Aug 1997, J. Kirschner, cultivated as JK 4670 (PRA, no. det. 35813); Ibidem, JK 4669 (PRA, no. det. 35807); Ibidem, JK 4667 (PRA, no. det. 35811); Ibidem, JK 4668 (PRA, no. det. 35809). – Pirin, Demjanica Chalet, stream banks, 2200 m, 8 Aug 1997, J. Kirschner, cultivated as JK 4326 (PRA, no. det. 35824). – Rila, Samokov, Borovec, Musalenski ezera, near the Musala Chalet (2389 m), 9 Aug 1990, J. Štěpánek & B. Kuzmanov, cultivated as JŠ 4826 (PRA, no. det. 25437); Ibidem, JŠ 4818 (PRA, no. det. 25436); Ibidem, JŠ 4285 (PRA, no. det. 25431); Ibidem, JŠ 4283 (PRA, no. det. 25430); Ibidem (PRA, no. det. 26188). – Samokov, in the valley of Maljovica River, between the resort of “Kompleks Maljovica” and the alpine chalet of Maljovica, 1750–2000 m, 8 Aug 1990, J. Štěpánek, cultivated as JŠ 4807 (PRA, no. det. 26192). – Samokov, Rila, above the Maljovica Chalet, 2000–2100 m, 8 Aug 1990, J. Štěpánek, cultivated as JŠ 4805 (PRA, no. det. 26191). – Samokov, near the Maljovica Chalet, 1900–2000 m, 8 Aug 1990, J. Štěpánek, cultivated as JŠ 4808 (PRA, no. det. 26190); Ibidem, JŠ 4280 (PRA, no. det. 25439). – Samokov, near the Maljovica Chalet, 9 Aug 1997, J. Kirschner, cultivated as JK 4695 (PRA, no. det. 35817). – Maljovica, straem banks between the Maljovica Chalet and the glacial cirque, 10 Aug 1997, [B. Trávníček], cultivated as JK 4333. (PRA, no. det. 35947). – Vitosha, Dragalevci, NE. slope of Mt. Malak Rezen (2191 m), Meča poljana, 1850–1950 m, ca. 42° 34’ N ”, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6905 (PRA, no. det. 25435); Ibidem, JŠ 6906 (PRA, no. det. 25433); Ibidem, JŠ 6904 (PRA, no. det. 26184). – Vitoša, village of Dragalevci, around the alpine shelter Alpicum on the summit of Černi vrch, 2280-2290 m, ca. 42° 34’ N, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6891 (PRA, no. det. 25434). – Dragalevci, NW. slopes below the summit of Mt. Goljam Rezen, ca. 2200–2250 m, ca. 42° 34’ N, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6983 (PRA, no. det. 26187). – Rhodopes, Čepelare, the Černatica Mts., Chvojna village, around Mt. Goljam Persenk (2091 m), in the pass between Mt. Goljam Persenk and Persenk, ca. 2 km W. of Skalni Mostove, ca. 1900–1950 m, ca. 41° 49’ N, ca. 24° 33’ E, 24 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 6918 (PRA, no. det. 26200); Ibidem, JŠ 6959 (PRA, no. det. 26200); Ibidem, JŠ 6913 (PRA, no. det. 26194); Ibidem, JŠ 6970 (PRA, no. det. 26193); Ibidem, JŠ 6916 (PRA, no. det. 26186); Ibidem, JŠ 6917 (PRA, no. det. 26185); Ibidem, JŠ 6914 (PRA, no. det. 26183); Ibidem, JŠ 6968 (PRA, no. det. 26182). – Čepelare, the Černatica Mts., Chvojna village, Mt. Goljam Persenk (2091 m), along the tourist path ca. 2–3 km W. of Skalni Mostove, ca. 1900–1950 m, ca. 41° 49’ N, 24° 32–33’ E, 24 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as JŠ 6939 (PRA, no. det. 26196). – Stara Planina, Zlatiško-Tetevenska planina, Teteven, village of Ribarica, Mt. Vežen (2198 m), the Kamenica Ridge, ca. 1950–2050 m, 20 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as TaB4 (PRA, no. det. 26199). – Zlatiško-Tetevenska planina, Teteven, village of Ribarica, Mt. Vežen (2198 m), a slopes between the pass of Ribariški Prohod and Gorni Vetroviti Preslap, ca. 1700 m, 20 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as TaB 5 (PRA, no. det. 26198). – Zlatiško-Tetevenska planina, Teteven, village of Ribarica, below the summit of Mt. Vežen (2198 m), ca. 2100 m, 20 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as TaB 3 (PRA, no. det. 26197). – Less certain identification: Rila, near the Ivan-Vasov Chalet, ca. 2200 m, 26 Jul 1989, B. Kuzmanov 89122, cultivated as JK T232 (PRA, no. det. 35815).
description: Published as part of Štěpánek, Jan & Kirschner, Jan, 2022, A hotspot of endemism: Oreophytic Taraxacum species (Compositae, Crepidinae) in the mountains of Bulgaria, pp. 1-139 in Phytotaxa 569 (1) on pages 98-100, DOI: 10.11646/phytotaxa.569.1.1, http://zenodo.org/record/7235182