Taraxacum bulgaricum van Soest (1976: 179)

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 : 51-54

. Taraxacum bulgaricum van Soest (1976: 179)

Type indication:—” Typus: Bulgaria, Blagoevgrad: Rila-Gebirge, am Sattel zwischen dem Tal der Černa Mesta und dem Iskâr-Tal , 2350 m; 4. 8. 1968, Merxmüller & Zollitsch (Herb. Z 12251)”; p. 180, fig. 6, “ holotype ” in the caption .

Type:— BULGARIA. Bezirk Blagoevgrad, Rila-Gebirge, am Sattel zwischen dem Tal der Černa Mesta und dem Iskâr-Tal, 2350 m, alpiner Rasen, 4 Aug 1968, H. Merxmüller & B. Zollitsch 24173, herb. B. Zollitsch 12251 ( M 243595 , holotype!) .

Note:—In the Bulgarian material collected by R. Doll (published 1978), T. bulgaricum exists under another two, misinterpreted names (usually only a part of the material under each name): T. helveticum and T. saasense .

Exsiccates:— Degen, Pl. Rumel. Orient., no. 96.

Plants small to almost dwarf, not slender, usually 4–8 (–10) cm tall, with a peculiar general habit characterized by dense, compact leaf rosette tightly appressed to the ground (immediately reflexed when cut off) and usually dominant, very broadly winged petioles. Plant base without tunic, subglabrous or sparsely whitish arachnoid. Leaves light yellowish green to bright green, unspotted or with scattered minute brown-purple spots, with sparse, very short arachnoid hairs proximally and along mid-vein, later ± glabrescent, oblong-ovate to ± oblong in outline, usually 3–6 (–8) cm long, 0.8–1.4 (–2.2) cm wide, pinnatilobed to pinnatisect, sometimes undivided and only dentate; terminal segment short, flat rhombic or trilobed, apical lobule usually abbreviated, forming a broadly triangular to narrowly acuminate mucro, basal lobules patent, usually narrowly deltoid-triangular with ± straight margins, sometimes pointing forwards or subrecurved, then distal margin convex, distal margin usually concave, entire, seldom with a tooth or an incision, proximal margin ± straight, entire; lateral segments (1) 3 (4), approximated, ± patent, deltoid-triangular or narrowly so, sometimes ± patent-hamate or slightly pointing forwards, usually 4–6 (–9) mm long, (3–) 5–7 mm wide at base, subacute to acute, distal margin straight or convex, often entire, sometimes with 1–3 short thin teeth or with an incision, proximal margin usually straight, or ± concave, rarely convex, usually entire, sometimes with 1–3 short teeth; interlobes short, ca. 1–2 (–4) mm long, 2–4 (–5) mm wide, not blotched, usually with one or several teeth, not bordered, rarely narrowly bordered brown-purple; mid-vein green or seldom purplish, petiole conspicuously broadly winged, usually (0.5–) 0.8–1.5 cm wide. Scapes thin, ± pale green, usually subglabrous, sometimes sparsely arachnoid, 3–5 cm tall at anthesis, later to 8–10 cm, shorter than, or ± equalling the leaf length. Capitulum small, to 2–2.5 cm wide, flat to subconvex, yellow to deep yellow. Involucre dark, almost blackish green, not pruinose, ca. 6 (–7) mm wide and subobconic-rounded at base. Outer phyllaries ± not imbricate to subimbricate, (7) 9–11 (14), tightly to loosely appressed, usually elliptical or ovate-lanceolate, sometimes lanceolate to narrowly lanceolate, most of them 4.3–5 mm long, 2–2.8 mm wide, the inner of them up to 6–7 mm long, 2–2.5 mm wide, dark olivaceous-green when fresh, usually evenly black-grey when dry, sometimes with a black middle line, border often ± absent, sometimes whitish-membranous, 0.1–0.3 mm wide, seldom suffused purplish along margins and at apex, rarely surface paler olivaceous-green, with a broader pale green border to 0.5 mm wide developed near phyllary base, margin sometimes glabrous but often ciliate throughout, apex flat or subcorniculate or subcarinate; inner phyllaries 10–13, of slightly unequal width, 10–12 mm long, greyish olivaceous-green, with 1–2 thin blackish lines, apex flat to callose. Outer ligules ± flat, striped light pinkish grey, apical teeth purple-grey, inner ligules canaliculate, their teeth light pinkish grey to yellow. Stigmas discoloured, greyish yellow-green, with darker pubescence outside, sometimes paler, light grey-yellow. Achenes (usually some sterile in a fruiting capitulum) ± deep grey to dark grey, sometimes lighter grey (light greyish stramineous when unripe), usually 3.3–4.5 (–4.9) mm long, 0.8–1.2 (–1.4) mm wide, body subturbinate, sparsely to very sparsely covered with erect minute squamules and spinules in upper 1/5–1/4, squamules sometimes arranged in 1–2 irregular rows, body ± gradually narrowing into a short conical to subconical cone (0.2–) 0.4–0.7 (– 0.9) mm long, cone usually coloured paler than the body; beak (1.5–) 5–5.5 mm long, slightly thickened, ca. 0.2–0.25 mm thick in the middle; pappus whitish, or yellowish white, (3.5–) 4–5 mm long. – Sexual. – Diploid (2n = 16, J. Kirschner, count from Pirin, under no. K-33/86). – Fig. 22, 23, 24.

Variation:—As a sexual taxon, T. bulgaricum is quite variable in its leaf shape (but outer and middle leaves always have a conspicuously broad petiole), presence/absence of spots on leaf surface, and in the length of achenes and beaks. A few plants sympatric with T. bulgaricum are suspected to represent recent hybrids with other taxa but further research is needed.

Habitat and distribution:—Subalpine and alpine stony or rocky grasslands, snowbeds, pastures, often on alkaline bedrock (limestone, serpentine), usually from 2200 to 2500 m. Taraxacum bulgaricum is relatively common in the alpine regions of Rila and Pirin, Bulgaria, and there is a reliable report on its occurrence in Greece ( Richards 1991: 551–552). Another distribution record is based on a herbarium specimen from the border between Bulgaria and North Macedonia, in the Belasica Mts. (Demir kapija). The IUCN conservation status is estimated as NT.

Relationships:— Taraxacum bulgaricum is an enormously distinctive taxon, characterized by a conspicuous leaf rosette (light, yellowish green colour of compactly arranged leaves very tightly appressed to the ground), dark involucre, and usually deep grey to dark grey, ± turbinate, relatively sparsely spinulose and squamulose achenes with a slightly thickened beak. As most of the sexually reproducing species in Taraxacum , it is a core taxon surrounded by a group of similar and probably related agamospermous taxa; these are the only species morphologically comparable with T. bulgaricum . Outside this circle of relatives, we were unable to find any similar taxon or group (see the discussion on the sectional relationships above).

Specimens examined:— BULGARIA. The Rila, near the Musala Chalet, 2500 m, 5 Aug 1930, J. Paczoski (POZNB, no. det. 19780). – Summit area of Mt. Musala, 2500 m, Degen, Pl. Rumel. Orient., no. 96, 25 Aug 1892, J. Wagner ( PRC, no. det. 21147; G, no. det. 22506; JE, no. det. 28524; WU, no. det. 21835, paratype); Ibidem, J. Wagner (G, no. det. 22503; WU, no. det. 9002). – Above the Skakavica Shelter, 2400 m, 31 Jul 1923, F. A. Novák 322 ( PRC, no. det. 21201). – N. slopes of Mt. Musala, 2750 m, 19 Aug 1936, J. Dostál 3952 ( PRC, no. det. 25091). – Borovec, Musalenski Ezera, between the Musala Chalet and Mt. Aleko, ca. 2450 m, 9 Aug 1990, J. Štěpánek (PRA, no. det. 27378). – Govedarci, valley of Maljovica River, valley between Mt. Kamilata and Mt. Orlovec, 1–1.5 km S. of the Maljovica Chalet, 2200–2250 m, 42° 11–12’ N, ca. 23° 25’ E, 10 Aug 1997, J. Štěpánek, cultivated as JŠ 6312b (PRA, no. det. 27377); Borovec, Musalenski Ezera, near the Ledenoto Ezero Chalet, shore of Ledeneto Ezero, ca. 2715 m, 9 Aug 1990, J. Štěpánek (PRA, no. det. 27373). – Rila, along a path between Vapa and Kovač, ca. 2600 m, 31 Jul 1987, P. Pyšek & J. Solnická (PRA, no. det. 27369). – Borovec, NE. slopes of Mt. Musala, ca. 2800 m, 9 Aug 1990, J. Štěpánek (PRA, no. det. 27365). – Mt. Musala, Aug 1936, A. Kozłowska (KRAM 37560!); 12 & 14 Aug 1936, J. Walas (KRAM 337373!). – A cirque NE. below Deno and Mt. Musala, ca. 2650 m, 14 Aug 1936, B. Pawłowski (KRAM 337372!). – Alpine belt of Mt. Musala, 25 Jul 1930, Ronniger (W, no. det. 8957). – Borovec, “Zavroščica” valley, SE. of Mt. Musala (2925 m), 25 Jul 1993, K. Sutorý (BRNM, no. det. 32385). – Rila, Skakavica, 1800–2000 m, 30 Jul 1923, J. Suza (BRNU, no. det. 30383). – Rila, Maljovica Chalet and the summit of Mt. Maljovica, 2400–2700 m, 16 Jul 1976, R. Doll as Taraxacum saasense (JE, no. det. 19044). – Towards the summit of Mt. Musala, ca. 2500–2800 m, 12 Jul 1976, [R. Doll] as Taraxacum helveticum (JE, no. det. 19407). – Rila, S. slope of Mt. Dodov vrch, ca. 1.8 km NNW. of Rilski Monastir, ca. 2550 m s.m., 28 Jun 1990, J. Štěpánková (PRA, no. det. 36023). – Mt. Musala, Ledeno ezero, 2850 m, 19 Aug 2011, D. Dimitrov, (SOM, no. det. 35898). – Mt. Musala, Mrkvička (SOM, no. det. 35892). – Rila, 4 Jul 1957, I. Bondev (SOM, no. det. 35827). – Rila, E. slope of Mt. Manču, 2550 m, 5 Jul 1957, I. Bondev (SOM, no. det. 35821). – The Pirin, Jel-tepe [Mt. Vichren], 2400 m, Jul [19]09, Dimonie (WU, no. det. 9003); Ibidem, 2500 m, Aug [19]09, Dimonie 296 ( PRC, no. det. 25092). – Pirin, alpine lake of Tevnoto ezero, 2500–2600 m, Aug 1982, H. Barešová, cultivated as JŠ 1003 (PRA, no. det. 27379, 2n = 16, counted by J. Kirschner under no. K-33/86); Ibidem, JŠ 1003 (PRA, no. det. 35521); Ibidem, JŠ 2720 (PRA, no. det. 27368 & 27367). – Bansko, Banderica valley, a valley between Mt. Graniten (2669 m) and Chvojnati vrch (2635 m), above Chvojnato ezero [lake], 2250–2350 m, 12 Aug 1990, J. Štěpánek (PRA, no. det. 27376); Ibidem, cultivated as JŠ 4874 (PRA, no. det. 27364). – Mt. Vichren, near the shore of the upper lake of the Vlachinski ezera, at the eastern foot of the Gredaro Ridge, ca. 1.5 km W. of Mt. Chvojnati vrch (2635 m), 2250–2300 m, 9 Aug 1997, J. Štěpánek, cultivated as JŠ 6305 (PRA, no. det. 27375). – Bansko, glacial cirque of Vasilaški Cirkus, along shores of Todorino ezero, ca. 2500 m, 14 Aug 1990, J. Štěpánek (PRA, no. det. 27374). – Vichren, near the shore of the middle lake of Vlachinski ezera, SW. foot of Chvojnati vrch (2635 m), 2350–2400 m, 9 Aug 1997, J. Štěpánek, cultivated as JŠ 6300 (PRA, no. det. 27371). – 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 (PRA, no. det. 27366). – Pirin, below the summit of Mt. Todorka, ca. 2600 m, 1987, B. Kuzmanov 8731, cultivated as JŠ 3256 (PRA, no. det. 25346). – Pirin, Sinaniškoto ezero, ca. 2100 m, 16 Sep 1970, Vihodcevski (KRAM 229237!). – Pirin, Demjanica Chalet, 2200 m, 8 Aug 1997, J. Kirschner, cultivated as JK 4323 (PRA, no. det. 30157). – Mt. Vichren area, slopes above Muratovo ezero, 8 Aug 1997, J. Kirschner, cultivated as JK 4322 (PRA, no. det. 30155). – Banderica, slopes of Mt. Vichren, 9 Aug 1997, J. Kirschner, cultivated as JK 4682 (PRA, no. det. 30153). – Belasica, alpine meadows near Demir Kapu [Demir Kapia Pass], Aug 1907, V. Stříbrný (ZT, no. det. 24438). – Less certain identification : —Rila, Seven Lakes, a mountain meadow below the chalet, sterile, 21 Jun 1964, W. Hempel (B, no. det. 21737).

Not located:—“In pascuis elatiorib. m. Č eder ..... Bulg. bor. occid. 883.” [partly illegible], 1883, [collector illegible] (WRSL, no. det. 28537).

Doubtful locality:—“ Bulgaria. In pratis humidis alpinis m. Vitoš.“, Jul 1887, J. Velenovský (PRC 401093, no. det. 25090) [up to now, T. bulgaricum has not been recorded from the Vitosha Mts. ] .