Taraxacum polozhiae Kurbatskiy
Creators: name: Kirschner, Jan
name: Štěpánek, Jan
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Asterales
Asteraceae
Taraxacum
Taraxacum polozhiae

description: 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.
description: Published as part of 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, pp. 1921-1935 in Phytotaxa 590 (1) on pages 1921-1935, DOI: 10.11646/phytotaxa.590.1.1, http://zenodo.org/record/7780271