Taraxacum pseudoceratoides 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 : 130-133

56. Taraxacum pseudoceratoides Kirschner & Štěpánek , sp. nov.

Type:— RUSSIA. The Altai Republic, Ongudai District, vicinity of Aktash village , subsaline meadows between the village and Chuya River , ca. 1340 m, ca. 50.306°N, 87.598°E, 4–5 Jul 1988, J. Kirschner, cultivated at Průhonice under no. JK 680 ( PRA, no. det. 37816, holotype) .

Etymology:—Similar to members of T. sect. Ceratoidea.

Diagnosis:—Species halophila inter sectiones Borealia et Ceratoidea media, characteres sectionis Ceratoideum aemulans , foliis laete cinereo-viridibus vel glauco-viridibus, stigmatibus saepissime laete luteis, phyllariis involucralibus exterioribus ± adpressis, viridibus, marginibus pallidioribus latis, acheniis plerumque dense squamulosis, corpore in pyramidem subcylindricam abrupte vel subabrupte transeunte, et flosculis pallide luteis notabilis.

Plants medium-sized, usually 13–23 cm tall. Plant base without tunic, with ± dense arachnoid indumentum among petiole bases. Petiole narrowly winged (more broadly in outer leaves), usually purplish. Leaves light greyish green, sometimes light glaucous-green, often bordered or suffused purplish, sparsely arachnoid to subglabrous, linear-oblong, linear-oblanceolate, rarely narrowly oblanceolate in outline, usually (5–) 7–10 (–12) × (0.7–) 1.2–1.6 (–2.0) cm, sometimes undivided and then entire or inconspicuously sinuate-dentate, usually pinnatilobed to pinnatipartite; terminal segment variable, not dominant, narrowly triangular to triangular, subacute to subobtuse, margins usually entire, sometimes with a tooth or incision, basal lobules short, patent to recurved; lateral segments usually 4–6, patent to recurved, usually with ± perpendicular, entire proximal margin and a gradually sloping, concave distal margin, entire or with a single incision or a tooth, distal part of lateral leaf segments often lingulate; interlobes variable, distal ones entire, proximal ones (and a basal part of segment’s distal margin) often denticulate; mid-vein pale green or suffused purplish. Scapes growing from the centre of rosette, light brownish green, distally often suffused purple, arachnoid, overtopping leaves. Capitulum light yellow, ca. 3.0– 3.5 cm wide. Involucre ± pruinose, light olivaceous-green to yellowish green, ca. (8–) 9–11 mm wide and broadly rounded to subtruncate at base. Outer phyllaries usually 12–19, appressed to loosely appressed, sometimes erect, lanceolate to ovate-lanceolate, usually (6–) 7–7.5 (–9) × (2.6–) 3.1–3.5 (–4.1) mm, surface generally light yellowish green to greyish green, sometimes suffused purplish (mostly distally), border whitish membranous, usually sharply delimited, 0.4–1.1 mm wide, often suffused light purple, middle zone yellowish olivaceous or greyish olivaceous, middle strip black-olivaceous, ca. 0.5 mm wide, margins ± not ciliate, apex with a dark green horn up to ca. 1 mm long; inner phyllaries 12–14 mm long, of ± invariable width, dark corniculate. Outer ligules flat to canaliculate, light yellow, faintly striped purplish outside, all apical teeth dirty purplish. Stigmas ± yellow, sometimes slightly pale greenish yellow, old stigmas slightly darkening. Pollen abundant, pollen grains conspicuously variable in size. Achenes light stramineous to light greyish stramineous, 3.7–4.3 × 1.0– 1.1 mm, body densely and conspicuously squamulose, partly also spinulose, in upper 1/3–1/2, in outer achenes squamulose throughout, abruptly to subabruptly narrowing in a subcylindrical cone 0.7–0.8 × 0.35–0.40 mm; beak 8.5–10.5 mm, pappus white, usually 6–7 mm long. – Agamospermous. – Fig. 91–93 .

Diagnostic notes:—When compared with other members of T. sect. Borealia, it is a strikingly outstanding taxon with a combination of pale greyish green leaf color, light yellow flowers, yellow stigmas and conspicuously squamulose achenes. Within T. sect. Ceratoidea it is best compared with T. bicorne , but is readily distinguishable by its outer phyllary and achene characters.

Distribution and habitat:— Taraxacum pseudoceratoides is known from a single macrolocality, a mozaic of wet saline habitats, pastures and wetlands between the village of Aktash and river Chuya. The sites are dominated by Hordeum brevisubulatum , accompanied by the white-flowered Taraxacum leucanthum and a yellow-flowered T. sinicum ; the elevation varies between 1330 and 1350 m.

Specimens examined:— RUSSIA. Altai Mts., Ongudai District, saline meadows near the village of Aktash , “ca. 1800 m ” [mistake: in reality it is about 1340 m], 4–5 Jul 1988, J. Kirschner 101, the above-ground plant part belonging to the root no. 101, later cultivated as JŠ 3405 ( PRA, no. det. 37818). – The Altai Republic, Ongudai District, vicinity of Aktash village, subsaline meadows between the village and Chuya River , ca. 1340 m, ca. 50.306°N, 87.598°E, 4–5 Jul 1988, J. Kirschner, cultivated at Průhonice under no. JK 3607 ( PRA, no. det. 37822). – Ibidem, cultivated as JK T163 from achenes no JŠ 3405 ( PRA, no. det. 37820) .

Taxa with names based on a rather inadequate material, with tentative interpretation

Figures

FIGURE 91. Taraxacum pseudoceratoides. General habit from different years of cultivation. A, a more compact growth (PRA, from cultivation JK 3607); B, more slender plants (PRA, no. det. 37816, a plant of the holotype sheet). Scale bar = 2 cm.

FIGURE 92. Taraxacum pseudoceratoides. The holotype. Photo M. Hladík.

FIGURE 93. Taraxacum pseudoceratoides. Achenes (PRA, no. det. 37820). Scale bar = 1 mm.