Taraxacum depauperatum 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

6. Taraxacum depauperatum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Respublika Altay] Sibiria austro-occid., montes Altaj, distr. Ongudaj, pagus Khabarovka , inter viam publicam et fl. Malyy Iľgumeň haud procul a pago, 29–30 jun 1988, J. Kirschner, cultivated as JŠ 3339 ( PRA, no. det. 35840, holotype; isotype: PRA, no. det. 36638) .

Etymology:—The name is derived from an unusually low number of outer phyllaries.

Diagnosis:—Species insignis foliis paulo glaucescentibus segmentis lateralibus numerosis lineari-triangularibus patentibus, phyllariis involucralibus exterioribus paucis, numero plerumque 7–8, adpressis vel laxe adpressis ovatis vel late ovatis, margine membranaceo 0.2–0.3 mm lato, acheniis brunneis, corpore in pyramidem brevem sensim transeunte.

Plants small, usually 8–12 cm tall. Petiole usually deep purple, sparsely arachnoid, narrow, unwinged; plant base with whitish hairs, tunic developed. Leaves slightly greyish green, subglabrous, oblanceolate to narrowly oblanceolate in outline, usually 4–10 × 1.3–2.7 cm, with a complicated shape pattern, pinnatisect, with 4–6 pairs of linear-triangular, narrowly triangular or ± linear lateral segments with distal margin (from usually broader lobe base) subconvex, often with basal lobules and teeth, apex acute to acuminate, proximal margin usually ± straight, entire or with a few minute teeth; terminal segment flat deltoid-triangular to almost tripartite, apex obtuse-angled, distal margin often concave, entire or with an incision, basal lobules patent to slightly forward-pointing, proximal margin entire; interlobes relatively broad (often to 4–6 mm), short, usually with lobules and/or teeth; mid-vein proximally purplish, otherwise light green. Scape purplish or brownish green, ± arachnoid, usually overtopping inflorescence. Capitulum lighter yellow, small, usually 2–2.5 cm wide. Involucre olivaceous green, 7–8 mm wide and rounded at base. Outer phyllaries few, 7–8 (10), appressed to ± loosely appressed, almost not imbricate, outer of them ovate to broadly ovate, 4.5–5 × 2.7–3.7 mm, innermost of them usually 5–6 × 1.9–2.5 mm, surface (light) olivaceous-green, border not very distinct, ± membranous, 0.2–0.3 (–0.4) mm wide, margin ciliate, sometimes denticulate, apex darker, corniculate; inner phyllaries (10–) 11–12 mm long, apex flat to callose. Outer ligules flat, striped grey-purple outside, inner ligule teeth dirty purplish. Stigmas darker discoloured, greyish light green, with darker pubescence outside. Pollen sparsely present, conspicuously irregular in size. Achenes ± medium brown, usually 3.2–3.8 × ca. 0.8 mm, body subdensely, distinctly spinulose in upper 1/3 (spinules erect-patent, relatively long), gradually narrowing into subcylindrical cone 0.6–0.7 (–0.8) mm long; beak 5–6 mm, pappus yellowish white, 5–5.5 mm long. – Agamosperm. – Fig. 7 .

Diagnostic note:— Taraxavum depauperatum is diagnosed by the low number of ovate, bordered outer phyllaries, dark discoloured stigmas and pure brown achenes. The achene body is covered with coarse spinules often curved upwards. Taraxacum depauperatum is similar to T. minuticarpum but differs from the latter in having pure brown achenes, lower number of outer phyllaries and a very different leaf shape.

Distribution and habitat:— Taraxacum depauperatum is known from a few localities in Ongudai and Ust’-Ulagan Districts in the Altai Mts. It grows on steppe or ruderalised steppe sites, within a relatively broad elevation span.

Specimens examined:—[ RUSSIA, Respublika Altay] Altai Mts., Ongudai District, Khabarovka, between the road and the river Malyy Iľgumeň [ca. 50° 41’ N, 86° 17’ E], 29–30 jun 1988, J. Kirschner, cultivated as JŠ 3339 ( PRA, no. det. 36638, with duplicates). – Altai Mts., Ongudai District , dry sites along the road in the village of Tuekta, 29 Jun 1988, J. Kirschner, cultivated as JŠ 3408 ( PRA, no. det. 36640). – Usť-Ulagan District , range of Kuraiskiy Khrebet, Mt. Aktash , 2600–3050 m, 3–4 Jul 1988, J. Kirschner, cultivated as T 168 ( PRA, no. det. 36948) .

Figures

FIGURE 7. Taraxacum depauperatum. A, General habit; B, Achenes (both from PRA, no. det. 35840, holotype).