Taraxacum polozhiae Kurbatskiy

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

24. Taraxacum polozhiae Kurbatskiy in Polozhiy (1980: 118)

Type:—[ RUSSIA] Abakanskaya Ekspeditsia , Khakasskiy okr., mezhdu r. Uybat i rch. Beey (sistemy r. Uybata), kamenistaya step’, 26 May – 10 Jun 1928, V. V. Reverdatto ( TK 002344 , holotype, photographs seen!) .

Etymology:—After Antonina Vasilyevna Polozhiy (1917–2003), a leading botanical personality at Tomsk State University, Russia. Plants small, usually to 10 (–12) cm tall. Petiole narrow, unwinged, purple, arachnoid; plant base with a well developed tunic. Leaves ± greyish green, arachnoid to sparsely so, mainly along mid-vein, with a complicated shape pattern, narrowly oblong to ± linear-oblong in outline, usually 5–10 × 0.9–2.2 cm, deeply and irregularly dissected in numerous, patent, linear-lingulate or linear segments to 2 mm wide, lateral segments usually 4–5 on each side but often asymmetrically arranged and with numerous, irregularly intercalated segment-like lobules and large teeth; terminal segment asymmetrically tripartite, with ± linear parts; interlobes long, narrow, with several patent linear lobules and large patent acute teeth; mid-vein purple. Scapes brownish green, slightly suffused purplish, arachnoid or sparsely arachnoid, ± overtopping leaves. Capitulum light yellow, 2.5–3 cm wide. Involucre light green to medium green, ca. 6– 7 mm wide and narrowly rounded at base. Outer phyllaries 11–16, appressed, ± not imbricate, ovate, ovate-lanceolate to ± lanceolate, usually 5.0–6.7 (–7.5) × (1.5–) 2.2–3.1 mm, surface light olivaceous-green (distally darker, suffused light purplish), with very gradual colour transitions, border not distinct, membranous to slightly whitish membranous, 0.3–0.6 mm wide, margin sparsely cilate to ± glabrous, apex dark corniculate; inner phyllaries 11–12 mm long, callose to corniculate. Outer ligules flat, striped grey with pinkish hue outside, inner ligule teeth dirty yellow. Stigmas ± pure yellow. Pollen (probably) present. Achenes dark red-brown, 3.0– 3.5 mm long, body spinulose above, cone ca. 0.5–0.6 mm long; beak 7–9 mm long, pappus ± white, 6–6.5 mm long. – Fig. 27 .

Diagnostic notes:— Taraxacum polozhiae is characterized by numerous, linear leaf segments and lobules, arachnoid leaves with a narrow, purple petiole, appressed light olivaceous-green outer phyllaries with an inconspicuous membranous border, yellow stigmas and red-brown achenes.

Distribution and habitat:— Taraxacum polozhiae is known from Khakassia, SW Siberia, and grows in gravelly steppe habitats.

Note:—The type material of the name T. polozhiae consists of very well developed, prepared and preserved plants at full anthesis, with a scape having almost ripe achenes. Thanks to the detailed photographic documentation (provided by Dr. I. Gureeva), we were able to compile a description almost completely comparable with those of the other taxa. It follows from the comparison that T. polozhiae belongs to T. sect. Dissecta , and represents a separate, well defined entity. Its relationships with T. sect. Stenoloba require further study but appear as probable.

Figures

FIGURE 27. Taraxacum polozhiae. A, General habit, and B, involucre (both from the holotype, TK). Photos I. Gureeva.