Taraxacum pubescens ( Fries 1814: 14 ) Fries (1843: 94)

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

25. Taraxacum pubescens ( Fries 1814: 14) Fries (1843: 94)

≡ Leontodon pubescens Fries (1814: 14)

[Type indication:—”Habitat in Siberia. Cel. Tilesius”]

Type:—” Leontodon n. sp. Sib. Ad Lenam fluvium”, [Tilesius] (LD, no. det. 17819, holotype; probably also an isotype of the name Leontodon dissectus , see below; isotype: “ Leontodon pubescens . Ad Lenam”, [with additional printed text on a separate label:] “Merck & Tilesius, ex herb. Rudolphi.)”, [Tilesius] (BM, no. det. 12147).

= Taraxacum dissectum ( Ledebour 1815: 555) Ledebour (1846: 814)

≡ Leontodon dissectus Ledebour (1815: 555)

[ Type indication:—” Hab. in Sibiria ad Lenam fluvium.”]

Type:—” Leontodon dissectus Ledeb. ” ad Lenam, ded. auctor [written by C. A. Meyer] ( LE, no. det. 6130, lectotype, designated by Tzvelev in Schischkin 1964: 539, see also Kirschner & Štěpánek 1996: 215).

= Taraxacum baicalense Schischkin (1964: 539) .

Type:—[ RUSSIA, Irkutskaya oblast] Oz. Baikal, zapadnoe poberezh’e, 53º s. sh, Ulus Tagota , sukhoi lug. [W. shore of Lake Baikal, 53º N, Tagot settlement, a dry meadow], 21 Jun 1928 , V. N. Sukachev, K. A. Rassadina & N. A. Bryzzhev 318 ( LE, no. det. 6052, holotype; isotype: LE!, photo PRA) .

Notes:—The date of publication of the name Leontodon dissectus is frequently given as 1812 ( Schischkin 1964, Kirschner & Štěpánek 1996). However, the study was orally presented by Ledebour before the Academy on January 19, 1814, and, as no preprints were issued of ser. 5 of the Memoires (A. Sennikov, pers. comm.), it is almost sure that the publication itself appeared in 1815. In the introductory paragraph, Ledebour (1815: 553) stated that the material evaluated was sent to him by Tilesius (W. G. Tilesius von Tilenau, 1769–1857), and on labels, Ledebour mentions the year 1813 as the acquisition date.

There are two specimens representing syntypes of Leontodon dissectus in LE. The typification was published by N. N. Tzvelev in Schischkin (1964: 539) and the type was annotated by N. N. Tzvelev in the herbarium. Although there is a specimen more suitable for the role of the lectotype (our no. det. 6132, a residual syntype, see the list of specimens examined) because of the presence of achenes and a more detailed label written by Ledebour himself, we retain the lectotype proposed by N. N. Tzvelev. Another specimen from the same gathering of Tilesius was deposited in Berlin (B), studied and photographed there by G. E. Haglund before the destruction of the B collection in the World War II. Haglund even retained a flower head; both the capitulum and the photographs clearly belong to what we call T. pubescens : “ad fl. Lenam”, [Tilesius], (originally B, photo deposited in S, and a separate capitulum, S 13–4553!).

A note on the synonymization: Although the name T. dissectum has been used quite frequently in the taxonomic literature, we refrain from proposing this name to be listed among conserved names. The name T. dissectum was used for a number of taxa, even for taxa belonging to several other sections, and we prefer the “clean” name, T. pubescens , with the detailed circumscription published in the present paper.

Plants small, to ca. 12 cm tall. Petioles narrow, unwinged, arachnoid, probably slightly purplish; plant base with dense yellowish to brownish hairs, covered with a well developed tunic. Leaves probably slightly greyish green, arachnoid to sparsely so, oblong-linear in outline, usually 3–8.5 × 0.9–2 cm, deeply pinnatisect, lateral lobes numerous, usually 5–8 pairs, lateral segments ± linear, sometimes with slightly dilated distal part, often with a few teeth or a lobule at distal margin base; interlobes narrow, short, often sparsely dentate or lobulate; terminal segment usually tripartite with distal part linear and patent, linear, often asymmetrical basal lobules; mid-vein hairy, pale greenish, sometimes suffused pinkish. Scapes brownish or pinkish green, densely hairy. Capitulum light mid-yellow, ca. 2.5 cm wide. Involucre deep green, ca. 7–9 mm wide and broadly rounded at base. Outer phyllaries usually 8–12, appressed, subimbricate, ovate to ovate-lanceolate, (3.5–) 5–6 mm long, (1.5–) 3.5–4.0 mm wide, with dark green middle strip and distinct broad whitish margin to ca. 1 mm wide, margin ciliate, apex usually ± flat; inner phyllaries to 11 mm long, ± flat. Outer ligules flat, faintly striped grey-pink outside. Stigmas pale greenish to ± yellow; pollen present, pollen grains irregular in size. Achenes greyish stramineous-brown, (3.8–) 4.0–4.4 (–4.6) mm long, 0.8–0.9 (–1.0) mm wide, gradually narrowing to a narrow subcylindrical cone (0.5–) 0.7–0.9 (–1.0) mm long, achene body almost smooth below, ± densely spinulose above, spinules thin, long, acute, suberect; beak ca. 6–7 mm long, pappus white, ca. (5.5–) 6–6.5 mm long. – Agamosperm. – Fig. 28 .

Diagnostic notes:— Taraxacum pubescens , with T. dissectum , the type of T. sect. Dissecta , as a synonym, does not represent a core taxon of this section. In many respects, particularly in its leaf shape and achene shape, it is similar to T. nobile Kirschner & Štěpánek , a species closer to T. sect. Suavia. The relatively long, greyish achenes, densely hairy leaves and scapes, ovate and broadly whitish bordered outer phyllaries are diagnostic. Taraxacum pubescens , although being closer to T. sect. Dissecta , belongs to an assemblage of forms intermediate between sections Dissecta , Stenoloba and Suavia.

Distribution and habitat:— Taraxacum pubescens is known from the SW. vicinity of Lake Baikal and the upper Lena River, and from several localities in Mongolia, and grows on dry steppe or secondary steppe slopes.

Specimens examined:—[ RUSSIA] “ Leontodon dissectus mihi” E Sibiria ad Lenam ded. am. [dedit amicus] Tilesius, Petrop. [Petropoli] 1813 [written by C. F. Ledebour] ( LE, no. det. 6132, residual syntype). – “ Leontodon dissectus mihi” ad Lenam Sibiriae [written by C. F. Ledebour] ( LE!, photo PRA). – “ad fl. Lenam”, [Tilesius], (originally B, photo deposited in S, and a separate capitulum, S 13–4553!). – Oz. Baikal, zapadnoe poberezh’e, 53º s. sh. [W. shore of Lake Baikal, 53º N], Улус [= Ulus, camp, aul, settlement] Tagota [Tagot settlement], sukhoi lug [a dry meadow], 21 Jun 1928, V. N. Sukachev, K. A. Rassadina & N. A. Bryzzhev 321 ( LE, no. det. 6131). – Republic of Buryatia, village of Petropavlovka, near the Dzhida River, 5 Jun 1965, G. A. Peshkova & Skudenkova ( NSK 0071828 , photo!). – Baikal Lake Region , “Balagavische Steppe, Mamurka”, May 1901, A. K. Cajander (S, no. det. 9250). – Baikal, W. shore between 53º and 55º N, Ol’khonskie Vorota , Bukhta Kurvut , 20 Jun 1928, V. N. Sukachev, K. A. Rassadina & N. A. Bryzzhev 254 ( LE, no. det. 7924). – Irkutsk Governorate , Verkholenskiy District ( Uezd ), around the village of Kachug , 3 Jul 1909, W. P. Drobow ( LE, no. det. 8180). – MONGOLIA. Northern Mongolia , steppe slopes E. of Tarialan village [ca. 49°37’ N, 101°59’ E] ( Tarjalang , between townships of Bulgan and Muren ), 1200–1300 m, 13 Aug 1965, M. Deyl & J. Soják, Iter Mongolicum 1965 , no. 3323 ( PR, no. det. 33599). – Northern Mongolia , in the city of Ulanbatar (Ulan-Bator), ruderal and steppe sites along the river, ca. 1300 m, 1 Sep 1966, J. Soják & V. Vašák 9025 ( PR, no. det. 33595). – Southern Mongolia , Gobi Altai , Gurvan-Sajchan-úl ( Gurvan-Sajchan ) Mts., ca. 25–40 km west of the township of Dalan-Zadgad , ca. 43°36’ N, 103°50’– 104°03’ E, meadows along a brook, 1600–2800 m, 25 Aug 1966, J. Soják & V. Vašák 8113 ( PR, no. det. 33597) .

Figures

FIGURE 28. Taraxacum pubescens. A, General habit; B, Details of involucre (both LE, no. det. 6132); C, Achenes (LE, no. det. 7924).