Taraxacum subsucculentum 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

1. Taraxacum subsucculentum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Respublika Altay] Sibiria austro-occid., montes Altaj, distr. Usť-Kan, secundum viarum ad pedem orient. clausae Jabaganskij Pereval [Altai, Ust-Kan District, along roads at the E. foot of Yabaganskiy Pereval (= Pass)], alt. ca. 1300 m, 27 Jun 1988, J. Kirschner, cultivated as JK 35, collected in 1990 ( PRA, no. det. 35980, holotype; isotypes: PRA, no. det. 36399) .

Etymology:—With slightly thickened (“subsucculent”) leaves.

Diagnosis:—Species notabilis petiolis conspicue purpureis angustis, foliis subglabris segmentis patentibus vel subrecurvis late linearibus vel lineari-lingulatis, phyllariis involucralibus exterioribus saturate olivaceo-viridibus vel obscure viridibus angustissime inconspicue marginatis, et acheniis rubro-brunneis brevibus crassiusculis, pyramide saepissime subconica crassa et perbrevi.

Plants small, usually to 10–12 cm tall. Petiole vivid purple, glabrous or with a few arachnoid hairs, narrow, unwinged or very narrowly winged; plant base with yellowish-brownish hairs, tunic developed. Leaves bright green to midgreen, of somewhat thicker appearance, glabrous or proximally very sparsely arachnoid, narrow, narrowly oblong in outline, usually 5–8 × 1–2.5 cm, pinnatisect, with 3–5 pairs of ± patent or recurved segments, patent segment usually ± linear (or linear-lingulate), distal margin straight to concave, with broader basal part with a single tooth or lobule, proximal margin straight, entire, recurved segments usually triangular or narrowly so, distal margin entire or, in proximal segments, sparsely dentate, ± straight, proximal margin straight, entire; interlobes narrow, usually 1.5–3 mm wide, entire or with a single patent tooth or lobule; terminal segment small, triangular to tripartite, entire or with a single tooth or incision, distal margin concave, basal lobules patent, sometimes ± recurved, proximal margin entire; mid-vein usually purple. Scapes greenish brown-pink, arachnoid or sparsely arachnoid, subequalling leaves. Capitulum lighter than mid-yellow, small, usually 2–2.5 cm wide. Involucre greyish deep green, usually 7–8 mm wide and rounded at base. Outer phyllaries (9) 10–12 (13), appressed, almost not imbricate, ovate to narrowly ovate, usually (5.5–) 6–7.5 (–8.5) × (2.2–) 3–3.7 (–4) mm, surface deep green to dark green, border indistinct, membranous to whitish membranous, 0.1–0.2 (–0.3) mm wide, margin ciliate, at least distally, apical part suffused reddish, apex flat to minutely corniculate; inner phyllaries 12–14 mm long, ± flat. Outer ligules flat, striped slightly pinkish deep grey, inner ligule teeth grey-pink. Stigmas greyish green, with darker pubescence outside. Pollen present, pollen grains irregular in size. Achenes short but robust, red-brown, (2.9–) 3.2–3.5 (–3.8) × (1.0–) 1.1–1.2 mm, body coarsely, relatively densely spinulose and squamulose in upper 1/3, subabruptly narrowing into a thick ± conical or subconical cone (0.3–) 0.4–0.5 (–0.6) mm long, 0.4–0.5 mm thick at base, 0.3–0.4 mm distally; beak 7.5–8.5 mm long, pappus ± white, 5–6 mm long. – Agamosperm. – Fig. 2 .

Diagnostic notes:—The most peculiar feature of this species is the length and shape of cone (conical, almost as long as broad, usually 0.5 mm long), and the thick and coarsely spinulose achene body. Bright purple petioles and the mid-vein are also conspicuous.

Distribution and habitat:— Taraxacum subsucculentum is a widely distributed species known from a series of localities in the Altai Mountains in Russia and from Mongolia. It grows on a wide range of dry, substeppe to semiruderal habitats, also on gravelly substrates along rivers, from ca. 600 m to 1900 m a.s.l.

Specimens examined:—[ RUSSIA, Respublika Altay] Altai, Ust-Kan District, along roads at the E. foot of Yabaganskiy Pereval, alt. ca. 1300 m, 27 Jun 1988, J. Kirschner, cultivated as JK 34 ( PRA, no. det. 35977). – Ibidem, cultivated as JK 33 ( PRA, no. det. 35979). – Altai, Ongudai District , in ruderalized steppe sites in the vicinity of Tuekta [940 m], 29 Jun 1988, J. Kirschner, cultivated as JK 32 ( PRA, no. det. 35964). – Altai, Ongudai District , saline meadows in the vicinity of Aktash village , ca. 1800 m, 4–5 Jul 1988, J. Kirschner, cultivated as JK 11 ( PRA, no. det. 35966). – Altai, Ongudai District , saline meadows in the vicinity of Aktash village , ca. 1800 m, 4–5 Jul 1988, J. Kirschner, cultivated as JK 10 ( PRA, no. det. 35970). – Altai, Kosh-Agach District , valley of the river Chuya , village of Chagan-Uzun, sandy and gravelly sites near the mouth of river Kuyakh-Tonar , ca. 1900 m, 5 Jul 1988, J. Kirschner, cultivated as JK 21 ( PRA, no. det. 35968). – Altai, Kosh-Agach District , valley of the river Chuya , village of ChaganUzun, sandy and gravelly sites near the mouth of river Kuyakh-Tonar , ca. 1900 m, 5 Jul 1988, J. Kirschner, cultivated as JŠ 3402 ( PRA, no. det. 35972) . – MONGOLIA. Central Mongolia, city of Ulan-Bator, dry places at the foot of Mt. Bogd-ul , south of the city, Aug 1990, J. Soják, cultivated as JK 727 ( PRA, no. det. 35982). – Ibidem, cultivated as JK 723 ( PRA, no. det. 35984). – Ibidem, cultivated as JK 740 ( PRA, no. det. 35975) .

Figures

FIGURE 2. Taraxacum subsucculentum. A, General habit; B, Achenes (both from PRA, no. det. 35980, holotype).