Taraxacum divulgatum Kirschner & Štěpánek, 2023

Kirschner, Jan & Štěpánek, Jan, 2023, A taxonomic revision of Taraxacum sect. Dissecta, a continental steppe group common in Siberia and adjacent regions of Central Asia, Phytotaxa 590 (1), pp. 1921-1935 : 1921-1935

9. Taraxacum divulgatum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Novosibirskaya oblast] Sibiria merid., urbs Novosibirsk, graminosis ruderalibusque ad crepidinem amnis Ob , contra plateam “Krasnyj Prospekt” in centro urbis Novosibirsk [Novosibirsk centre, dam of River Ob, ruderalized grassy sites facing the street of Krasny Prospekt], 22 Oct 1985, J. Kirschner, cultivated as JŠ 2686, collected in 1988 ( PRA, no. det. 35959, holotype; isotype: PRA, no. det. 36694) .

Etymology:—Widespread.

Exsiccates:— Taraxaca Exs., no. 1357–1367.

Diagnosis:—Species distincta, satis vulgata, insignis foliis lobo terminali plerumque tripartito, segmentis lateralibus patentibus angustis, phyllariis involucralibus exterioribus adpressis, aequabiliter saturate olivaceo-viridibus marginibus angustissimis fere invisibilibus, stigmatibus pallide viridescentibus, necnon acheniis brevibus, mediocriter brunneis paulo rubescentibus vel brunneosubcinnamomeis, pyramide brevi anguste cylindrica.

Plants small, rarely to medium-sized, usually to 12 cm tall. Petiole brownish green, narrow, unwinged or very narrowly winged, sparsely arachnoid to glabrescent; plant base with whitish hairs, tunic ± developed. Leaves ± mid-green, not spotted, sparsely arachnoid on mid-vein beneath or ± glabrous, narrowly oblong in outline, usually 6–11 × (1.7–) 2–2.5 (–3) cm, deeply pinnatisect, with (4) 5–6 (7) pairs of patent, less often subrecurved narrowly triangular-deltoid or lineardeltoid lateral segments with distal margin concave, less often straight or sigmoid, entire or with 1 (–2) basal incisions or lobules, proximal margin ± straight, entire; terminal segment most often tripartite with linear or narrowly triangular distal part and linear to linear-triangular, patent or forward-pointing entire basal lobules; interlobes narrow, distinct, usually 3–6 × 2 (–2.5) mm, entire or with a few patent teeth, sometimes dark bordered; mid-vein adaxially usually faintly suffused brownish pink, or light green. Scapes brownish green, arachnoid or densely arachnoid, subequalling leaves. Capitulum yellow, 2.5–3.5 cm wide. Involucre olivaceous-green, not pruinose or slightly so, usually 9–10 mm wide and broadly rounded at base. Outer phyllaries usually 12–14, appressed, ± not imbricate, ovate-lanceolate, less often to ovate, the outermost ones sometimes linear-lanceolate, ca. 1 mm wide, (5–) 6–7.5 (–8.5) × (1–) 2–2.8 (–3.1) mm, surface homogeneously deep olivaceous-green, sometimes with a thin blackish green middle line, border almost invisible, membranous, 0.1 (–0.2) mm wide, margin ciliate, apical part often suffused reddish, apex flat to minutely dark corniculate; inner phyllaries 12–14 mm long, flat to callose. Outer ligules flat, striped pale pinkish grey to light grey, inner ligule teeth grey-purple. Stigmas very pale greenish yellow. Pollen present, pollen grains irregular in size. Achenes slightly reddish medium brown or light medium brown with a cinnamon tinge, 2.9–3.8 × 0.7–0.8 mm, body subdensely but distinctly spinulose in upper 1/4, subgradually narrowing into a thin cylindrical cone 0.7–0.9 × 0.2– 0.25 mm; beak 7–8 mm long, pappus yellowish white, 5–5.5 mm long. – Agamosperm. – Fig. 10 .

Diagnostic notes:—The appressed, evenly olivaceous-green, borderless outer phyllaries, in combination with the numerous, narrow, patent leaf segments, and the peculiar medium brown achene colour of this species are diagnostic within T. sect. Dissecta . When compared with other members of T. sect. Dissecta , T. divulgatum seems to be very close to T. jacuticum . Although the comparison is rather hindered by the scanty material of T. jacuticum , the following differences characterize T. divulgatum : primarily it is the medium brown colour of achenes, with a cinnamon or slightly reddish tinge (achenes are deep red-brown in T. jacuticum ), longer outer phyllaries with a very narrow, almost invisible border, a longer beak and paler stigmas.

Distribution and ecology:— Taraxacum divulgatum was sampled at almost all the Siberian localities visited by us in 1985: Novosibirsk, Irkutsk, Baikal Lake and Bratsk. In addition, it was also found on the slopes of the Klyuchevskaya Volcano, Kamchatka. It grows on a wide range of dry grassland habitats, even semiruderal, and on gravelly and sandy sites along rivers or lakes, usually between 100 and 500 m a.s.l.

Specimens examined:—[ RUSSIA, Irkutskaya oblast] S. Siberia, city of Irkutsk, grasslands in the centre, near the church, not far from Angara hotel, 25 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2688 ( PRA, no. det. 35961). – Ibidem, cultivated as JŠ 2689 ( PRA, no. det. 35963). – S. Siberia, city of Irkutsk, grasslands and ruderal sites along the banks of Angara River in the city centre, 25 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2693 ( PRA, no. det. 36700). – City of Irkutsk, Baikal Lake , village of Listvyanka , steppe slopes above the port in the village [ca. 51° 51’ N, 104° 52’ E, ca. 500 m a.s.l.], 26 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2536 ( PRA, no. det. 36696). – S. Siberia, town of Bratsk, west shore of the “Bratskoe More” reservoir, about 10 km from the dam, not far from the “Bratsk” hotel, 27–28 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2578 ( PRA, no. det. 36698). – S. Siberia, town of Bratsk, west shore of the “Bratskoe More” reservoir, about 10 km from the dam, not far from the “Bratsk” hotel, 27–28 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2576 ( PRA, no. det. 36691). – Ibidem, cultivated as JŠ 2577 ( PRA, no. det. 36702). – [Novosibirskaya oblast] Novosibirsk, a quarter called Akademgorodok, in lawns in the vicinity of the “Dom Uchonych” hotel, 21 Jun 1988, J. Kirschner, cultivated as JK 84 ( PRA, no. det. 36697). – Novosibirsk, grasslands and semiruderal sites along the embankment of the River Ob , near Krasny Prospekt in the city centre, 22 Oct 1985, J. Kirschner & J. Štěpánek, cultivated as JŠ 2562 ( PRA, no. det. 36695). – Ibidem, cultivated as JŠ 1578/9 ( PRA, no. det. 36699). – The Far East [Kamchatsky krai], Kamchatka, Klyuchevskaya Volcano, near old volcanological station on the N slope of the volcano, 56°09’ N, 160°48’ E, 926 m, 20 Jul 2003, R. K. Brummitt & S. McDonald 20853, cultivated as JŠ 8158 ( PRA, no. det. 36965); Ibidem, cultivated as JŠ 8943 ( PRA, no. det. 36967) .

Figures

FIGURE 10. Taraxacum divulgatum. A, General habit; B, Achenes (both from PRA, no. det. 35959, holotype).