Taraxacum fornicatum 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 : 44-45

9. Taraxacum fornicatum Štěpánek & Kirschner , sp. nov.

Type:— Bulgaria, montes Rila , opp. Govedarci , vallis flum. Maljovica, in pratis et caespitibus circum deversorium in loco ‘ Kompleks Maljovica’, ca. 1700 m, ca. 42° 12–13’ N, 23° 25’ E, 10 Aug 1997, J. Štěpánek et al., cultivated as JŠ 6493, collected in 1999 ( PRA, no. det. 36054, holotype; isotypes: PRA, no. det. 36089, and duplicates) .

Etymology:—Vaulted, arched, arcuate (from Latin: fornix, arch).

Diagnosis:—Plantae notabiles phyllariis involucralibus exterioribus basi adpressis, superne laxe adpressis, saepissime ovato-lanceolatis ad 4 mm latis, obscure viridibus, in sicco atroviridibus, in marginem sordide scariosam, 0.2–0.4 mm latam abrupte transeuntibus, acheniis superne breviter spinulosis (squamulis carentibus), corpore in pyramidem conicam, 0.3–0.5 mm longam subabrupte abeuntibus.

Plants relatively small, of ± compact growth, 6–11 cm tall. Plant base without tunic, with ± dense brownish hairs among petiole bases. Petiole winged to broadly winged, pale green, often distally adaxially suffused purplish, 1.5–2.5 cm long. Leaves erect-patent to subpatent, slightly greyish green, later ± suffused purplish when exposed to direct sunlight, sparsely arachnoid, narrowly oblanceolate to ± spatulate in outline, usually 5–12 × 1–2.5 cm, pinnatifid to pinnatisect, outer leaves often undivided, narrowly spatulate, only remotely denticulate; terminal segment ± dominant, ± elongated, helmet-shaped to triangular, usually (1–) 1.5–2.5 × 1.3–2.5 cm, obtusely acute to obtuse, distal margin subconvex to subsigmoid, with 1–2 distinct teeth on each side, basal lobules acute, recurved, sometimes ± patent, proximal margin subconcave to ± straight, entire; lateral segments in 2–3 pairs, deltoid-triangular to narrowly so, ± recurved to patent, acute, distal margin ± convex to subsigmoid, entire, proximal margin ± concave, entire; interlobes long and broad, usually 5–12 × (2–) 4–9 mm, green, ± not bordered, entire, rarely with a few minute teeth, margin often raised; mid-vein adaxially purplish in proximal half or throughout. Scapes pale green, medium densely arachnoid, ± equalling leaves. Capitulum relatively large, 3–3.5 cm wide, flat, dark yellow. Involucre ± not pruinose, 8–9 (–10) mm wide and rounded at base. Outer phyllaries 13–19, tightly appressed at base, distally loosely appressed, some sometimes arcuate, subimbricate, reaching 1/2 of the inner, usually lanceolate to ovate-lanceolate, most frequently 6–8 × (2.0–) 2.5–4 mm, usually evenly dark green (black-green when dry), sometimes with broad pale greenish borders at base (in young capitula), most often with an abrupt transition in a dirty scarious border 0.2–0.4 mm wide, margin distally minutely ciliate, apex flat; inner phyllaries ca. 12 mm long, of ± unequal width. Outer ligules flat, relatively broad, striped grey to dark grey outside, apical teeth black, inner ligules canaliculate, their teeth dirty yellow to greyish. Stigmas ± long, medium dark discoloured, greyish yellow-green, hairs of the outer pubescence with a dark distal half. Pollen abundant, pollen grains irregular in size. Achenes light brownish to deep stramineous-brown, slender, 3.5–4.1 × 0.8–1.0 mm, body subdensely shortly spinulose (squamules absent) in upper 1/5–1/6, ± subabruptly narrowing into a short subconical to conical cone (0.3–) 0.4–0.5 mm long; beak 6–9 mm long; pappus whitish to dirty white, 5.5–6 mm long. – Agamosperm. – Fig. 15D, 19, 20.

Diagnostic notes:— Taraxacum fornicatum is characterized by relatively large, dark outer phyllaries with ± distinct but very narrow border. Achenes with a very short, conical cone with a subabrupt transition in the subdensely spinulose (not squamulose) achene body are also diagnostic.

Distribution and habitat:—In Bulgaria, Taraxacum fornicatum is an unusually widely distributed mountain species; it was found to occur in the Rila, Pirin and the Rodopi, and, in all likelihood, it also grows in the Vitosha. Its habitats include shores of alpine lakes, and marshy subalpine to alpine grasslands. Its IUCN conservation status is estimated as LC.

Specimens examined:— BULGARIA. The Rodopi, the Čepelare Mts., Chvojna village , around Mt. Goljam Persenk (2091 m), wet mossy places along a brook, ca. 1 km W. of Skalni Mostove , ca. 1800 m, ca. 41° 49’ N, 24° 33–34’ E, 24 Jul 1998, J. Štěpánek et al., cultivated as JŠ 6792 ( PRA, no. det. 25422). – Pirin, Bansko , Mt. Vichren , shores of the lower, bigger lake of Vlachinski ezera, E. foot of Gredaro Ridge , 2250–2300 m, 41° 45’ N, 23° 23’ E, 9 Aug 1997, J. Štěpánek, cultivated as JŠ 6553 ( PRA, no. det. 36068). – Rila, Govedarci , valley of Maljovica River , in the Kompleks Maljovica , ca. 42° 12–13’ N, 23° 25’ E, 10 Aug 1997, J. Štěpánek et al., cultivated as JŠ 6507 ( PRA, no. det. 36091). – Less certain identification : Sofia, the Vitosha, village of Dragalevci , NW. slopes below the summit of Mt. Goljam Rezen (2277 m), ca. 2200–2250 m, ca. 42° 34’ N, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6978 ( PRA, no. det. 36072). – Sofia, the Vitosha, village of Dragalevci , NE. slope of Mt. Goljam Rezen (2277 m), above Meča poljana, ca. 2050–2150 m, ca. 42° 34’ N, ca. 23° 18’ E, 27 Jul 1998, J. Štěpánek, cultivated as JŠ 6808 ( PRA, no. det. 36066) .