Taraxacum sublateritium 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 : 66

23. Taraxacum sublateritium Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Altai Republic] the Altai Mts., the Kurai Range [Kuraiskiy Khrebet], slopes of Mt. Aktash , 2600–3050 m, 3–4 Jul 1988, J. Kirschner, cultivated as T 144 ( PRA, no. det. 35859, holotype) .

Etymology:—Close to T. lateritium , or light brick red.

Diagnosis:— Taraxaci lateritii maxime affine sed notabile petiolis alatis, acheniis pallide fulvo-cinnamomeis vel pallidissime roseolobrunnescentibus, corpore superne sparsissime minute spunuloso vel tuberculato, in pyramidem conicam persensim transeunte.

Plants small to medium-sized, 9–14 cm tall. Petiole green or with a purplish mid-vein, narrowly winged to winged, ± glabrous, tunic absent. Leaves light green to mid-green, ± glabrous, with mid-vein pale green, blade ± narrowly oblanceolate, most often undivided, dentate or sinuate-dentate, or pinnatilobed, with 2–3 pairs of broadly triangular, subpatent, entire lobes, (4–) 6–9 × 1.2–2.0 cm, [some leaves, developing later in cultivation, are pinnatipartite, relatively large, to 13 × 4.5 cm, and are not considered as characteristic of the species], terminal segment usually not discernible, sometimes long, narrowly triangular, subacute. Scape brownish green to pinkish green, some scapes initially sparsely arachnoid, all later glabrescent, subequalling leaves; at fruiting stage, scapes bent downwards. Capitulum yellow, ca. 2.5–3.5 cm wide. Involucre blackish olivaceous-green, ca. 9 mm wide and ± broadly rounded at base. Outer phyllaries 11–16, appressed, subimbricate, outer of them broadly ovate to ovate, inner of them ovate-lanceolate, usually 6.5–8.5 × 2.5–3.3 (–5.0) mm, usually evenly black-green, border often almost absent, sometimes ± distinct but extremely narrow, up to 0.1 mm wide, margin distally shortly and sparsely ciliate, apex corniculate in early capitula, with thick black horns in late capitula. Inner phyllaries 12–15 mm long, dark olivaceous-green, often coalescing, with a narrow black middle line or with two submarginal lines, apex usually black corniculate. Outer ligules narrow, ± flat to canaliculate, striped grey-pink to light grey outside, teeth blackish, inner ligule teeth greyish. Stigmas dark discoloured, grey-green with black pubescence outside. Pollen present, pollen grains irregular in size. Achenes light fulvous-cinnamon to very light pinkish brown, 4.8–5.3 × (1.0–) 1.1–1.2 (–1.3) mm, body sparsely and shortly (0.1–0.2 mm) spinulose in upper 1/4, otherwise smooth with longitudinal ridges, very gradually narrowing into a conical to subconical cone (0.8–) 1.0– 1.1 mm long, 0.6–0.7 mm thick at base, 0.4–0.5 mm distally; beak thin, 0.15–0.20 mm, ca. 6–7 mm long, pappus white, ca. 5.5–6 mm long. – Agamospermous. – Fig. 3E , 41 .

Diagnostic notes:—Plants from the Altai resemble T. lateritium sensu lato; achenes of the Altai plants are close to those of plant from the Mesenkin syntype of T. lateritium but T. sublateritium is much more sparsely spinulose and the leaves are different. Taraxacum sublateritium differs from all the syntypes of T. lateritium primarily in ± winged petioles and a very sparsely spinulose or only tuberculate achene body. Taraxacum altaicum is a species even closer than T. lateritium but clearly distinct from T. sublateritium in having imbricate, subappressed to erect-patent or patent outer phyllaries with an indistinct, membranous border, the ± thickened beak, a longer pappus, and very narrowly winged to unwinged petioles. In the achene characters, T. sublateritium and T. altaicum are very similar but the former usually has a thinner cone.

Distribution:—Known only from the type locality region, around Mt. Aktash in the Kurai Range.

Specimens examined:—[ RUSSIA, Altai Republic] the Altai Mts., the Kurai Range [Kuraiskiy Khrebet], slopes of Mt. Aktash , 2600–3050 m, 3–4 Jul 1988, J. Kirschner, cultivated as T 144 ( PRA, no. det. 35859 and duplicates). – Ibidem, cultivated as JŠ 3377 ( PRA, no. det. 36739) .

Figures

FIGURE 3. Details of involucres of Taraxacum species from the Altai, in alphabetic order. A, T. abhorrens (PRA, JŠ 2703); B, T. candicans (PRA, no. det. 35860); C, T. compitale (PRA, no. det. 35857); D, T. crassicarpum (PRA, no. det. 35858); E, T. sublateritium (PRA, no. det. 35859); F, T. leptoceras (PRA, T 83); G, T. mimosiflorum (PRA, no. det. 35853). Scale bars: A, E = 2 mm; B, C, D, F, G = 5 mm.

FIGURE 41. Taraxacum sublateritium. A, general habit (PRA, no. det. 35859); B, achenes (PRA, from specimens cultivated as T 144). Achenes are more pinkish under daylight. The early leaves are undivided or regularly shallowly lobed while the late leaves, developing in full blossom in cultivation, are luxuriant and deeply pinnatipartite.