Taraxacum perdecorum 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 : 50-53

17. Taraxacum perdecorum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Altai Republic] USSR, Sibiria austro-occid., montes Altaj, distr. Šebalino, secundum viam publicam non procul a pago Topučaja , ca. 2000 m, 27 Jun 1988 , J. Kirschner, cultivated as JŠ 3407 ( PRA, no. det. 35992, holotype) .

Etymology:—Extremely elegant, very graceful.

Diagnosis:—Species spectabilis, bene dignoscenda foliis pallide viridibus lobis lateralibus patentibus, interlobiis saepissime subtus maculatis, phyllariis involucralibus exterioribus angustissimis, plerumque lineari-lanceolatis, marginibus indistinctis angustis, apice corniculatis vel cornibus nigrescentibus praeditis, acheniis ± gracilibus et pyramide brevi, crassa, conica.

Plants medium-sized, to 11–15 cm tall. Petiole light green, sometimes suffused pinkish, sparsely arachnoid, broadly winged to winged in outer leaves, ± unwinged in inner ones, tunic absent. Leaves light green to vivid green, sparsely arachnoid adaxially, later ± glabrescent, mid-vein green or faintly purplish, blade oblong-oblanceolate in outline, usually 6–9 × 1.5–2.5 cm, pinnatipartite to pinnatisect; terminal segment ± deltoid or flat triangular, distal margin concave or straight, entire, proximal margin subconvex, entire; lateral segments in 3–4 pairs, perfectly patent, deltoid-triangular, narrowly deltoid or linear-deltoid, distal margin straight or subconcave, entire, rarely with a few minute teeth, proximal margin usually straight, entire; interlobes distinct, entire or with a single tooth or lobule, abaxially often bordered or blotched brownish purple. Scapes light brownish green, very sparsely arachnoid or (later) glabrous, equalling or ± overtopping leaves. Capitulum yellow, usually 3.0– 3.5 cm wide. Involucre deep olivaceous-green or dark olivaceous-green, ca. (8–) 9–10 mm wide and broadly rounded at base. Outer phyllaries 12–16, inserted loosely from one another, not imbricate, erect-patent, linear-lanceolate to narrowly lanceolate, usually 7–9 × (1.3–) 2.2–2.9 mm, ± evenly olivaceous-green to blackish olivaceous-green, sometimes with a thin black middle line, border not distinct, often suffused purplish, usually (whitish) membranous, to 0.1 mm wide (rarely to 0.2–0.3 mm at the very base of the phyllary), margin glabrous or very sparsely ciliate distally, apex corniculate, in later capitula with thin or thick black horns to 2 mm long; inner phyllaries 11–15 mm long, dark olivaceous-green, corniculate or flat. Outer ligules ± canaliculate to flat, striped blackish or blackish green or blackish-purplish, teeth dark, inner ligule teeth yellow or greyish yellow. Stigmas ± yellow or dirty yellow or light greyish yellow. Pollen present, pollen grains irregular in size. Achenes light greyish (light) stramineous-brown, ± slender, (3.2–) 3.3–3.7 (–4.1) × 0.7–0.8 (–0.9) mm, body subsparsely spinulose and squamulose in upper 1/4–1/5, gradually narrowing into a thick conical cone (0.3–) 0.4–0.6 mm long, ca. 0.4 mm thick at base, ca. 0.3 mm distally; beak thin (ca. 0.1 mm), ca. 9–10 mm long, pappus white, 5.5–6.0 mm long. – Agamospermous. – Fig. 4B , 31 , 32 .

Diagnostic notes:—When reaching the Altai Mts., JK was very surprised to see the local meadow dandelion flora dominated by a previously unknown form, distinct in having very narrow, straight, erect, erect-patent to ± patent outer phyllaries, often blotched interlobes, long, usually patent leaf lateral segments and other remarkable features. Later, this entity turned out to be composed of three species (also T. leptoceras and T. peracre ), but T. perdecorum remained one of the most conspicuous and widespread taxa in the Altai. Within the group of T. perdecorum – T. ochotense , this species is characterized by erect-patent, very narrow outer phyllaries, leaves with mostly deltoid and entire segments, paler stigmas and the short, conical cone. In its leaf shape, T. perdecorum approaches T. shumushuense Kitamura (1933: 124) , a species ± intermediate between T. sect. Borealia and T. sect. Mongolica , described from the Kuriles. These two species substantially differ in outer phyllaries (of a very broad shape in T. shumushuense ) and achene features (achenes thick, with a longer cone in T. shumushuense ). When T. perdecorum is compared with T. acricorne , its blotched interlobes and broadly conical cone are diagnostic.

Distribution:— Taraxacum perdecorum obviously is among the most frequent and the most widely distributed dandelions in the Altai. It was documented from more than a dozen sites across the whole Altai, from the Usť-Kan District in the west to the Ongudai District in the east. Moreover, in the west, it reaches also the part of the Altai situated in Kazakhstan. It grows in various ± humid meadows and in the subalpine vegetation, and along rivers.

Specimens examined:—[ RUSSIA, Altai Republic] Gorno-Altaisk, Shebalino District, vicinity of Topuchaya village , 27 Jun 1988, J. Kirschner , cultivated as JŠ 3407 ( PRA, no. det. 35994). – W. Altai, Usť-Kan District , meadows in the Yabaganskii Pereval Pass , ca. 1500–1600 m, 27 Jun 1988, J. Kirschner , cultivated as T 216 ( PRA, no. det. 35996). – Ibidem, cultivated as T 41 ( PRA, no. det. 35991). – Ibidem ( PRA, no. det. 35798). – Altai Mts., the Kurai Range [Kuraiskiy Khrebet], slopes of Mt. Aktash , 2600–3050 m, 3–4 Jul 1988, J. Kirschner, cultivated as JŠ 3377 ( PRA, no. det. 35987). – Usť-Ulagan District , dry sites along the road in the vicinity of Aktash village , 2 Jul 1988, J. Kirschner, cultivated as T 81 ( PRA, no. det. 35989). – Ibidem, cultivated as T 80 ( PRA, no. det. 35796). – Gorno-Altaisk, Shebalino District , along the river Sema in the vicinity of Cherga, 24–25 Jun 1988, J. Kirschner, cultivated as JŠ 3318 ( PRA, no. det. 33409). – Ibidem, cultivated as JŠ 3317 ( PRA, no. det. 33413). – Shebalino District , sandy shores of Katun River near Usť-Sema village , 26 Jun 1988, J. Kirschner, cultivated as JŠ 3323 ( PRA, no. det. 33411). – Ongudai District , valley of the river Chuya , meadows and slopes near the mouth of the Ai-Gulak River , ca. 1050 m, 2 Jul 1988, J. Kirschner, cultivated as T 74 ( PRA, no. det. 33415). – Ibidem, cultivated as JŠ 3355 ( PRA, no. det. 35775). – Ongudai District , grasslands, semisteppe sites and gravelly banks in the vicinity of the confluence of rivers Katun’ and Chuya, 1 Jul 1988, J. Kirschner, cultivated as JŠ 3348 ( PRA, no. det. 35792). – Ibidem, cultivated as JŠ 3349 ( PRA, no. det. 35795). – Ongudai District , meadows ca. 10 km to south-east of Iodro, ca. 950m, 1 Jul 1988, J. Kirschner, cultivated as JŠ 3350 ( PRA, no. det. 35773). – Usť-Ulagan District , range of Aigulakskii Khrebet, meadows in the vicinity of Myortvye Ozera (Lakes) near the pass Ulaganskiy Pereval, 1850–1900 m, 2 Jul 1988, J. Kirschner, cultivated as T 54 ( PRA, no. det. 35789). – Shebalino District , semi-steppe sites below the village of Akťyol, 800–900 m, 25 Jun 1988, J. Kirschner, cultivated as T 65 ( PRA, no. det. 35791). – Ongudai District , Khabarovka, between the main road and Maly Iľgumen’ river , 29–30 Jun 1988, J. Kirschner, cultivated as T 58 ( PRA, no. det. 35802). – Ibidem, cultivated as T 60 ( PRA, no. det. 35800). – Ongudai District , meadows in the vicinity of Seminskiy Pereval [pass], ca. 1760 m, 27 Jun 1988, J. Kirschner, cultivated as JŠ 3327 ( PRA, no. det. 35804). – Ongudai District , Kupchegen’, Bol’shoi Iľgumen’ Valley , valley bottom ca. 5.5 km WNW of the village, 50°38”25’ N, 86°21”07’ E, 1001 m, 5 Aug 2011, J. Danihelka, cult. as JŠ 9697 ( PRA, no. det. 37768). – Less certain identification :— KAZAKHSTAN. East Kazakhstan, the Altai Mts., banks of Berel R., by a bridge ca. 1.6 km ESE of Yazovka, ca. 1200 m, 49.4425°N, 86.3672°E, 26 Jun 2006, P. Koutecký, cult. as JŠ 8182 ( PRA, no. det. 37808). – Ibidem, cult. as JŠ 8181 ( PRA, no. det. 37810) .

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 31. Taraxacum perdecorum. The holotype. Photo M. Hladík.

FIGURE 32. Taraxacum perdecorum. A, general habit (PRA, no. det. 35992, holotype); B, achenes (PRA, JŠ 3407).