Taraxacum melanospilum 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 : 82-84

4. Taraxacum melanospilum Štěpánek & Kirschner , sp. nov.

Type:— Bulgaria, Stará planina, pars mont. Zlatiško-Tetevenska planina, opp. Teteven, pag. Ribarica, mons Vežen (2198 m), locus scaturiginosus et ad rivulum in depressione, ca. 2150 m, 20 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as. TaB 2d ( B 2 d), collected in 2000 ( PRA, no. det. 30622, holotype ; isotypes: PRA) .

Etymology:—With black spots (derived from Greek μελαϛ, black, and σπίλος, spot).

Exsiccates:— Taraxaca Exs., no. 1063–1066.

Diagnosis:—Plantae petiolis alatis roseis vel purpureis, foliis saturate gramineo-viridibus, saepe paulo grisescentibus, sparse maculatis, maculis 0.5–2.5 mm latis, phyllariis involucralibus exterioribus basi adpressis, ceterum erectis, ovatis vel ovato-lanceolatis, in sicco atro-viridibus, in marginem pallidam, 0.2–0.5 mm latam sensim (ad basin) vel abrupte (in parte distali) transeuntibus, acheniis obscure brunneo-cinereis, corpore superne dense spinuloso-squamulosis, pyramide brevi, conica vel subconica, notabiles.

Plants medium-sized, relatively robust, usually 7–11 cm tall. Plant base without tunic (or with a few dark brown remnants of old petioles), with sparse brownish hairs among petiole bases. Petiole broadly winged, light pink to ± deep purple. Leaves numerous, variously subpatent to ± prostrate, deep mid-green to ± greyish green, adaxially sparsely spotted brown-purple (spots 0.5–2.5 mm wide), subglabrous, usually with sparse hairs confined to mid-vein, narrowly elliptical to elliptical in outline, usually 6–12 × 2–4 cm, pinnatisect; terminal segment usually broadly triangular, flat rhombic or broadly flat helmet-shaped, usually 1–1.5 × 1.5–2 cm, often with a triangular to lingulate mucro, distal margin ± dictinctly sigmoid, less often ± straight, entire or seldom with a few teeth on basal lobules, basal lobules most often arcuate-recurved, sometimes straight, patent to subrecurved, ± acuminate, proximal margin usually concave, entire; lateral segments in 4–6 pairs, usually narrowly triangular, ± patent to hamate-subrecurved, usually 1–2 cm long, 5–8 mm wide at base, distal margin convex to sigmoid, entire or very often irregularly filiform-dentate, sometimes with a deep, lobule-like incision, proximal margin subconcave to ± straight, often raised, entire or sparsely denticulate; interlobes narrow, usually 2–6 × 2–6 mm, margin entire or with one or several long teeth, raised, narrowly bordered brown-purple; mid-vein usually pale, less often slightly brownish. Scapes pale greenish at anthesis, later suffused purple below capitulum, ± sparsely arachnoid, usually ± equalling leaves. Capitulum 3–4 cm wide, ± flat, yellow. Involucre not pruinose, usually 8–9 mm wide and subtruncate to broadly rounded-subobconical at base. Outer phyllaries 15–19, appressed proximally, distally erect, ± imbricate, ovate to elliptical to ovate-lanceolate, usually 6–7.5 × (3–) 3.5–4 mm, most of the abaxial surface ± evenly dark olivaceous (black-green when dry), in the basal half of a phyllary with a gradual transition, in the distal half with ± abrupt transition in a pale, dirty whitish border 0.2–0.5 mm wide, margin almost glabrous, apex flat, usually much paler, lingulate, obtuse, 1–1.5 × 1 mm; inner phyllaries 12–13 mm long, of ± equal width. Outer ligules flat, striped dark greyish outside, apical teeth smoky yellow, inner ligules canaliculate, its apical teeth ± black. Stigmas dark discoloured, greenish yellow, with a dense long black pubescence outside. Pollen abundant, pollen grains irregular in size. Achenes deep brown-grey, (3.9–) 4.0-4.5 (–4.7) × (0.9–) 1.1– 1.3 mm (the widest dimension just below the cone base), body with ± dense, erect to suberect, ± short broad spinules, often coalescing in squamules in upper 1/4–1/5, ± abruptly narrowing into a conical to subconical cone (0.4–) 0.5–0.8 mm long, 0.40–0.45 mm thick at base, ca. 0.3 mm distally; beak slightly thickened, (6–) 7–8.5 mm long, pappus light brownish-whitish to pale brownish, 6–7 (–7.5) mm long. Relatively often, a certain proportion of empty, infertile achenes is found in a fruiting capitulum. – Agamosperm. – Fig. 45 , 46A .

Diagnostic notes:—While the core species of T. sect. Bulgarica are morphologically and geographically centred in the vicinity of T. bulgaricum , T. melanospilum seems to be rather marginal in both respects. We can mention the spotted leaves with a comparatively small terminal segment and ± narrow lateral ones, ± imbricate, conspicuously bordered outer phyllaries, and, in particular, the deep brown-grey achenes with a slightly thickened beak as diagnostic. Taraxacum melanospilum exhibits certain relationships with the members of T. sect. Rhodocarpa (= T. sect. Alpestria), the group of T. alpestre (Tausch) Reichenb. , and with T. elegantissimum and T. pseudoalpestre , species of the Romanian Southern Carpathians. It differs from the latter taxa in having much smaller and less conspicuous leaf terminal segment, spotted leaves, loosely appressed (not arcuate-patent) and conspicuously bordered outer phyllaries, and deep brown-grey (not light straw-brown or pale, even whitish brownish stramineous) achenes. Within T. sect. Bulgarica, it approaches T. musalae in the achene colour and some features of leaves. Taraxacum musalae , however, has outer phyllaries short, 4–6.5 mm long (not 6–7.5 mm, as in T. melanospilum ), beak short, usually 4–6 mm long (not 6–8.5 mm) and pappus pure white (not pale brownish-whitish, which is a diagnostic feature of T. melanospilum ).

There is a striking similarity between artificial, sexual hybrids obtained from the crosses of two sexual species, T. linearisquameum van Soest and T. bulgaricum , and more robust plants of T. melanospilum , which might suggest the origin of the latter, a derived agamospermous entity.

Distribution and habitat:—Quite frequent in the western and central Stara Planina [Mts.] above the timberline; we consider it as endemic to that area. It grows in wet grasslands, and usually along brooks in subalpine and alpine meadows and pastures, between (1450–) 1600 and 2200 m. Its IUCN conservation status is estimated as LC.

Specimens examined:— BULGARIA. The Stara Planina Mts. , Zlatiško-Tetevenska planina, Teteven , village of Ribarica , Mt. Vežen (2198 m), ca. 2150 m, 20 Jul 1998, R. Bělohlávková, J. Štěpánek, V. D. Vladimirov & D. Petkova, cultivated as TaB 2a ( PRA, no. det. 26307) ; Ibidem, TaB 2b ( B 2 b) ( PRA, no. det. 26309) ; Ibidem, TaB 2c ( PRA, no. det. 26308) ; Ibidem, TaB 2d ( B 2 d) ( PRA, no. det. 26310). – Zlatiško-Tetevenska planina, Teteven , village of Ribarica , Mt. Vežen (2198 m), a ridge between Mt. Kamenica and the pass of Ribariški Prohod , ca. 1800–1950 m, ca. 42° 45’ N, ca. 24° 26–27’ E, 20 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 7582 ( PRA, no. det. 26303) ; Ibidem, JŠ 7583 ( PRA, no. det. 26302). – Zlatiško-Tetevenska planina , Teteven , village of Ribarica, Mt. Vežen (2198 m), the Kamenica Ridge, E. of the pass of Kamennata porta, ca. 1950–2050 m, ca. 42° 45’ N, ca. 24° 26’ E, 20 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 6974 ( PRA, no. det. 26295) ; Ibidem, JŠ 7579 ( PRA, no. det. 26306) ; Ibidem, JŠ 7580 ( PRA, no. det. 26306, 26305) ; Ibidem, JŠ 7581 ( PRA, no. det. 26304) ; Ibidem, JŠ 6780 ( PRA, no. det. 27484). – Zlatiško-Tetevenska planina , Teteven , village of Ribarica , below the summit of Mt. Vežen (2198 m), ca. 2100–2150 m, ca. 42° 45’ N, ca. 24° 24’ E, 20 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 6989 ( PRA, no. det. 26294) ; Ibidem, JŠ 6990 ( PRA, no. det. 26293) ; Ibidem, JŠ 6784 ( PRA, no. det. 27481). – Trojan , the Trojanska Planina , southern slopes of the pass of Trojanski Prohod, 1450–1550 m, 42° 46–47’ N, 24° 35–36’ E, 21 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 7000. ( PRA, no. det. 26296). – Trojan , the Trojanska Planina , between the pass of Karčov preslap and Mt. Ušite (1637 m), ca. 1600 m, 42° 47–48’ N, 24° 29–30’ E, 21 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 7018 ( PRA, no. det. 26297). – Trojan , the Trojanska Planina , the alpine chalet of Kozja Stena , 1500–1600 m, ca. 42° 47’ N, ca. 24° 32’ E, 21 Jul 1998, J. Štěpánek, R. Bělohlávková, V. D. Vladimirov & D. Petkova, cultivated as JŠ 7010 ( PRA, no. det. 26298) ; Ibidem, JŠ 7546 ( PRA, no. det. 26299) ; Ibidem, JŠ 7547 ( PRA, no. det. 26300) ; Ibidem, JŠ 7550 ( PRA, no. det. 26301) .

Figures

FIGURE 45. Taraxacum melanospilum. General habit (PRA, no. det. 26293). Scale bar = 2 cm.

FIGURE 46. Achenes of Taraxacum melanospilum (A, PRA, no. det. 26310) and T. circense (B, PRA, no. det 26148). Scale bars = 1 mm.