Taraxacum terrestre 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 : 65-67

7. Taraxacum terrestre Štěpánek & Kirschner , sp. nov.

Type:— Bulgaria, montes Rila , opp. Samokov , pagus Borovec , Musalenski ezera, locis graminosis petrosisque in vicinitate lacus alpini ca. 500-800 m situ merid.-occid. a casa alpina Musala (2389 m), ca. 2450 m, 9 Aug 1990, J. Štěpánek, cultivated as JŠ 4813, collected in 1993 ( PRA, no. det. 36044, holotype; isotype: PRA, no. det. 36046, and duplicates) .

Etymology:—Terrestrial, earthbound (derived from Latin terra, earth, land).

Diagnosis:—Plantae acheniis pure cinereis vel pallide cinereo-brunnescentibus, tenuibus, 0.7–0.9 mm latis, superne sparse breviter spinuloso-squamulosis, corpore in pyramidem subconicam crassiusculam 0.6–0.8 mm longam sensim transeunte, foliis glaberrimis, vivide virescentibus, lobus lateralibus numerosis angustis et interlobiis saepissime denticulatis bene dignoscendae.

Plants small, ± compact, 7–9 cm tall, later after anthesis up to 20 cm tall. Plant base ± without tunic, with dense brownish hairs among petiole bases. Petiole pale green, broadly winged, 1 (–1.5) cm long. Leaves numerous, appressed to the ground or some ± patent, ± vivid green, glabrous, narrowly elliptical to narrowly oblanceolate in outline, usually 4–6 × 1–1.8 cm, pinnatisect; terminal segment relatively small, broadly triangular to triangular-helmet-shaped, usually 4–6 (–12) × 5–10 (–14) mm, acute, sometimes narrowed in a lingulate to triangular mucro, distal margin sigmoid or concave, or subconvex, entire or sometimes with an incision in the middle, basal lobules hamate-recurved to ± patent, acuminate, proximal margin concave to ± straight, entire; lateral segments in 4–5 (–7) pairs, usually bird-wing-like, generally hamate-recurved, usually 5–9 mm long, 4–6 mm wide at base, with a broader base and an elongated, narrow distal part, distal margin convex to sigmoid, usually with a medium-sized, ± broad tooth near the base, sometimes with another few minute teeth or entire, proximal margin concave to ± straight, ± entire; interlobes short, relatively narrow, usually 1.5–3 × 2 mm, with an undulate and raised margin, usually with 1–2 teeth, not bordered or with a faintly purplish border; mid-vein pale to purplish pink. Scapes pale greenish, initially sparsely arachnoid, later glabrescent, ± glabrous at anthesis, ± longer than leaf length. Capitulum ca. 3 cm wide, flat, yellow. Involucre not pruinose, ca. 8 mm wide and ± obconical at base. Outer phyllaries 12–15, appressed, ± not imbricate, reaching 2/5–1/2 of the inner, narrowly lanceolate to ovate-lanceolate, usually 5–7 × 2.5–3 mm, dark olivaceous-green, darker distally and along margins, with a gradual transition in a dirty membranous border 0.05–0.2 mm wide, margin minutely ciliate, sometimes only in distal 1/3, apex flat; inner phyllaries 12–13 mm long, of ± equal width. Outer ligules flat, striped ± light grey-purple outside, apical teeth black-purple, inner ligules canaliculate, their apical teeth dirty yellow. Stigmas long, discoloured, light yellow-green to light greyish green, pubescence hairs with black apical part. Pollen present, pollen grains irregular in size. Achenes pure light grey to light brownish grey, longitudinal ridges not developed, usually 4.2–5.3 × 0.7–0.9 mm, body with sparse short spinules and squamules in upper 1/6, with a gradual transition into a subconical cone 0.6–0.8 × 0.3–0.4 mm; beak 4–6.5 mm, pappus 5.5–6 mm, white. – Agamosperm. – Fig. 32C, 34.

Diagnostic notes:— Taraxacum terrestre is distinct in having numerous, relatively narrow lateral leaf segments, dentate interlobes with raised margins, and long, slender achenes with a sparse spinulosity. In its leaf shape, it approaches T. circense which has light brownish beige achenes with a shorter conical cone, longer interlobes, and outer phyllaries loosely appressed. Taraxacum terrestre , and probably also T. circense , may be rather marginal to T. sect. Bulgarica, showing a certain affinity to T. sect. Crocea.

Distribution and habitat:—Known from the Mt. Musala area, the Rila, around 2500 m. It grows on wet stony grasslands along shores of alpine lakes. Its IUCN conservation status is estimated as VU.

Specimens examined:— BULGARIA. The Rila , Borovec , lakes of Musalenski ezera, near an alpine lake ca. 500–800 m SW. of the Musala Chalet (2389 m), ca. 2450 m, 9 Aug 1990, J. Štěpánek, cultivated as JŠ 4825 ( PRA, no. det. 36048) .