Taraxacum tortisquameum Kirschner & Štěpánek, 2025

Kirschner, Jan, Štěpánek, Jan & Buryy, Vladimir V., 2025, Towards a revision of Taraxacum sect. Borealia (Compositae, Crepidinae) in Siberia and the continental Far East, with special reference to the dandelions of the Altai and Kamchatka, Phytotaxa 679 (1), pp. 1-147 : 78-82

31. Taraxacum tortisquameum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Altai Republic] USSR, Sibiria austro-occid., montes Altaj, pars Kurajskij Chrebet , in decl. montium circa m. Aktaš, alt. ca. 2600–3050 m, 3-4 Jul 1988 , J. Kirschner , cultivated as T 166 ( PRA, no. det. 35983, holotype) .

Etymology:—With twisted phyllaries.

Note:—The name T. tortisquameum occurs on herbarium labels in Scandinavian herbaria as an invalid name meant for another taxon, with the authorship of Dahlstedt or H. Lindberg.

Diagnosis:—Plantae robustae, heterophyllae, foliis plerumque indivisis dentatis vel lobulatis, phyllariis involucralibus exterioribus numerosis, patentibus vel suberecto-patentibus, anguste lanceolatis interdum tortilibus, apice atro-cornutis, achenii corpore persparse squamuloso, in pyramidem subcylindricam sensim transeunte et rostro longo notabiles.

Plants not tall but of robust appearance, usually 10–15 cm tall. Petiole light purplish, narrowly to broadly winged, initially sparsely arachnoid, later glabrescent, plant base without tunic. Leaves deep green to ± light green, with purplish mid-vein, subglabrous to glabrous, ± oblanceolate to oblanceolate-spathulate in outline, many leaves in rosettes undivided, densely irregularly dentate with short unequal teeth or short lobules, some leaves with a dominant terminal segment with dentate or lobulate margins and 1–3 pairs of short dentate lobes, a few leaves pinnatifid, with a broad, obtusely triangular terminal segment with sparsely denticulate distal margins, and lateral segments ± patent to patentrecurved, deltoid-triangular to ± triangular, usually with distal margin sparsely denticulate and proximal one ± entire. Scapes usually growing from outside the leaf rosette, brownish green, arachnoid, ± overtopping leaves. Capitulum yellow (outer ligules getting purplish during drying), 2.5–3.0 cm wide. Involucre dark olivaceous-green, ca. 10–11 mm wide and broadly rounded at base. Outer phyllaries 17–21, patent to suberect-patent, usually arranged in a single plane, not imbricate, usually narrowly lanceolate, 8.5–10.0 (–12.0) × (2.0–) 2.6–3.3 mm, surface deep olivaceous-green to blackish green with black middle line, border paler green and membranous, not distinct, 0.1 (–0.3) mm wide, often suffused purplish, margins ± glabrous, flat or often revolute (then outer phyllaries ± tortuous), apex with dark thick horn to 1.5 mm long; inner phyllaries 16–18 mm long, corniculate. Outer ligules ± flat, striped (light) grey-purple or grey outside, teeth deep grey purple, inner ligule teeth ± purplish or light greyish. Stigmas greenish, with blackish pubescence outside. Pollen present, pollen grains irregular in size. Achenes very light greyish stramineous-brown, (4.1–) 4.3–4.8 × (0.8–) 0.9–1.1 mm, body with very sparse, short but robust erect-patent bi- or tricuspidate squamules and occasional spinules in upper 1/4, body very gradually narrowing into a ± subconical to subcylindrical cone (0.6–) 0.7–0.8 mm long, ca. 0.4 mm thick at base, ca. 0.3 mm distally, occasionally with 1–2 minute spinules in proximal 1/3, beak thin, 9.5–11.5 mm long, pappus white, 5.5–6 mm long. – Agamospermous. – Fig. 4E , 51 , 52 .

Diagnostic notes:— Taraxacum tortisquameum is very noticeable in the field because of its very numerous (17– 21), narrow, usually perfectly patent, straight, flat or ± tortuous outer phyllaries. Its achenes are relatively long, very sparsely squamulose above, with a slender body very gradually narrowing in a subconical to subcylindrical cone 0.6–0.8 mm long.

Distribution:—It was collected at seven sites around Mt. Aktash in the Kurai Range in the Central Altai, growing in subalpine meadows above 2600 m. Another group of gatherings comes from the Yuzhno-Chuiskiy range, the Altai, not far from the previous locality.

Specimens examined:—[ RUSSIA, Altai Republic] Usť-Ulagan District, range of Kuraiskii Khrebet, Mt. Aktash (3121 m), subalpine and alpine slopes, 2500–2600 m, 3 Jul 1988, J. Kirschner , cultivated from achenes of JŠ 3387 as T 166 ( PRA, no. det. 36774). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), steep alpine slopes W of the lake on the Belen’kiy Brook , 2700–3500 m, 4 Jul 1988, J. Kirschner , cultivated from achenes JŠ 3400 as T 130 ( PRA, no. det. 36770, 37755). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), slopes of a deep valley W of the lake on the Belen’kiy Brook , 2000–2200 m, 4 Jul 1988, J. Kirschner , cultivated from achenes of JŠ 3397 as T 164 ( PRA, no. det. 36769, 37757). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), subalpine and alpine western slopes, 2500–2600 m, 3 Jul 1988, J. Kirschner , cultivated from achenes of JŠ 3387 as T 167 ( PRA, no. det. 36765, 37761). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), subalpine and alpine western slopes, 2500–2600 m, 3 Jul 1988, J. Kirschner , cultivated from achenes of JŠ 3386 as T 168 ( PRA, no. det. 36767, 37759). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), subalpine and alpine western slopes, 2500–2600 m, 3 Jul 1988, J. Kirschner , cultivated from achenes JŠ 3381 as T 170 ( PRA, no. det. 36763, 37765). – Usť-Ulagan District , range of Kuraiskii Khrebet , Mt. Aktash (3121 m), wet, mossy subalpine slopes with Taraxacum glabrum DC., 2500 –2600 m, 3 Jul 1988, J. Kirschner , cultivated as T 172 ( PRA, no. det. 36772, 37753). – [ RUSSIA, Altai Republic] Kosh-Agach District , Kosh-Agach village , Yuzhno-Chuiskiy Range , Tara (Dara) River valley, 49°39”27.8’ N, 88°13”34.8’ E, 2221 m, 26 Jul 2011, J. Danihelka , cult. as JŠ 9688 ( PRA, no. det. 37784). – Ibidem , cult. as JŠ 9689 ( PRA, no. det. 37786). – [ RUSSIA, Altai Republic] Severo-Chuiskiy Range , ca. 16 km SW of Aktash, bank of Eshtykol R., 2135 m, 50°12’59”N, 87°26’04”E, 11 Aug. 2003, A. Chlebicki & M. Suková, cult. as JŠ 7858 ( PRA, no. det. 37792) .

Figures

FIGURE 4. Details of involucres of Taraxacum species from the Altai, in alphabetic order. A, T. peracre (PRA, T 55); B, T. perdecorum (PRA, no. det. 35992); C, T. peschkovae (PRA, no. det. 35855); D, T. seminudum (PRA, JŠ 2597); E, T. tortisquameum (PRA, no. det. 35983); F, T. xanthellum (PRA, T 173); G, T. xiphodon (PRA, T 162). Scale bars: D = 2 mm; A–C, E–G = 5 mm.

FIGURE 51. Taraxacum tortisquameum. The holotype. Photo M. Hladík.

FIGURE 52. Taraxacum tortisquameum. A, general habit (PRA, no. det. 35983, holotype); B, achenes (PRA, from specimens cultivated as JŠ 3387/46).