Taraxacum atropurpureum Kirschner, Štěpánek, Buryy, Chernyagina & Efimov, 2022

Kirschner, Jan, Štěpánek, Jan, Buryy, Vladimir V., Chernyagina, Olga A. & Efimov, Petr G., 2022, A new species of Taraxacum sect. Arctica (Asteraceae, Crepidinae) from northern Kamchatka, Russia, with a synoptic survey and a nomenclator of the section in Russia, Phytotaxa 550 (2), pp. 171-185 : 172-175

Taraxacum atropurpureum Kirschner, Štěpánek, Buryy, Chernyagina & Efimov , sp. nov.

Type:— RUSSIAN FEDERATION. The Far East: Poluostrov Kamchatka, vostochnoe poberezh’e, Kamchatskiy Kraj , Karaginskiy Raion , bassein reki Tymlat , srednee techenie r. Tolyatovayam , syroy lug v poyme (bezlesnoy) [ N. Kamchatka, eastern coast, Karaginskiy District, Tymlat River basin, middle stream of Tolyatovayam River, a humid meadow in a treeless floodplain, 59°24’39.6” N, 162°33’17.1” E, 219 m], 10 Aug 2011, O. Chernyagina ( KAM, no. det. 36880, holotype; isotype: PRA, no. det. 37010) .

Diagnosis:—Planta nostra spectabilis, differt a speciebus ceteris sectionis Arcticorum acheniis atropurpureis corpore sparse breviter spinuloso, in pyramidem brevissimam conicam 0.3–0.5 mm longam sensim transeunte, antheris polline carentibus, ligulis saturate luteis tubulosis vel raro subtubulosis, scapis glabris violascentibus, phyllariis involucralibus exterioribus paucis pruinosis et foliis pinnatisectis segmentis lateralibus patentibus.

Plants small, slender, usually to 5 cm, later to 15 cm tall. Petiole thin, unwinged, usually purplish, glabrous, tunic absent. Leaves ± mid-green, glabrous, narrowly oblanceolate in outline, ca. 3.5–6 (–9.5) × 0.7–1.7 (–2.0) cm, pinnatipartite to pinnatisect, with 2–4 pairs of patent, narrowly deltoid, subacute lateral segments, distal margin ± straight to subconcave, entire, proximal margin ± straight, usually entire, sometimes with a single basal short triangular tooth; terminal segment broadly triangular to trilobed, lobes ± obtuse; interlobes distinct, 1–3 mm wide, entire; midvein usually ± suffused purplish. Scapes glabrous, brownish green, often suffused purplish, subequalling leaves. Capitulum mid-yellow to deep yellow, not fully opening, ca. 1 (–1.5) cm wide, florets not numerous (ca. 25–35). Involucre pruinose, greyish olivaceous-green, ca. 4–5 mm wide and narrowly rounded to subobconical at base. Outer phyllaries 7–10, posture variable, some ± appressed or loosely appressed, some erect, several or even a majority often erect-arcuate (with recurved distal part), broadly ovate to ovate, ca. (3.5–) 3.7–4.1 (–4.5) × (1.5–) 1.8–2.2 (–2.5) mm, surface strongly pruinose, evenly dark greyish olivaceous green, sometimes dark olivaceous, distally purplish, border not very distinct (sometimes ± absent), white-membranous, ca. 0.1–0.2 mm wide, margin glabrous, apex flat. Ligules ± tubular, rarely with a proximal slit, outer ones striped black-purple outside. Stigmas dark discoloured, not exserted. Pollen absent. Achenes blackish purple or very dark grey-purple, ca. 3.9–4.2 × 0.8–0.9 mm, spinulosity very sparse, reaching cone lower (or even middle) part, composed of short, broadly conical spinules usually to 0.1 mm long, body very gradually and indistinctly narrowing into a ± conical cone 0.3–0.5 mm long; beak thin (0.10–0.15 mm), ca. 4 mm long, pappus white, 4.2–4.5 mm long. – Agamospermous. – Fig. 2 , 3 , 4B, C, D .

Diagnostic notes:— Taraxacum atropurpureum is a species belonging to the core of T. sect. Arctica on the basis of a low number of ovate, deep grey-olivaceous, almost unbordered outer phyllaries (without cornicles or horns), slender, low growth, very narrow petioles, and relatively small, dark coloured achenes with a body sparsely spinulose or tuberculate above, with a very gradual transition into a short conical cone, and a relatively short beak.

The diagnostic characters of T. atropurpureum include tubular, rarely subtubular, deep yellow florets, the absence of pollen, dark stigmas, pruinose outer phyllaries with a very narrow, indistinct border, inner phyllaries pruinose, glabrous leaves and scapes, patent leaf lobes, and, in particular, dark, blackish violet or black-purple achenes with a conical cone 0.3–0.5 mm long; the cone is difficult to discern from the achene body because of the very gradual transition and short spinules ascending to the middle part of the cone.

A more detailed comparison with other members of Taraxacum sect. Arctica :—In several respects, T. atropurpureum is close to T. semitubulosum . They share tubular florets and the absence of pollen, both being rather rare characters in T. sect. Arctica. Taraxacum semitubulosum differs from our plant in its pale yellow flowers, regularly arcuate-recurved, not pruinose, ± borderless outer phyllaries, and leaf segments usually ± recurved to subrecurved; the most conspicuous difference consists in the achene characters, as T. semitubulosum has achenes greyish stramineousbrown and much more densely spinulose and squamulose.Another similar species is T. sibiricum , readily distinguishable by its dark grey-brown achenes and polliniferous anthers. Among species lacking pollen, T. atropurpureum is similar to T. mujense (distinct in having light red achenes, flat ligules and deltoid leaf lateral segments) and to T. czukoticum (ligules flat, leaves narrow, remotely and shallowly lobed).

Distribution:—The distribution range of T. atropurpureum , on the basis of the herbarium material, is confined to Karaginskiy District, Kamchatka Region, in the northern part of Kamchatka Peninsula (see the map on Fig. 1 ).

Note:—The report of the occurrence of T. semitubulosum in the Penzhina River basin, Kamchatka Region ( Kharkevich & Tzvelev 1978: 842), might represent another locality of T. atropurpureum and should be checked as the previously known geographical range of T. semitubulosum is almost 2000 km remote from that of T. atropurpureum . Tzvelev (1992), however, did not include T. semitubulosum in the Flora of the Soviet Far East, although the fate of the Penzhina River record was not explicitly explained (the voucher specimen of the Penzhina record has not been located in LE).

Habitat:—The two localities with the occurrence of T. atropurpureum were documented in detail. The seemingly low elevation (between 218 m and 330 m a.s.l.) nevertheless represents a subalpine vegetation, either a krummholz mosaic with Pinus pumila (Pall.) Regel and Alnus alnobetula subsp. fruticosa (Rupr.) Raus (with patches of snow accumulation and places with a rich subalpine vegetation characterized by Rhodiola rosea L., Oxyria digyna (L.) Hill, Veronica grandiflora Gaertn. , Primula cuneifolia Ledeb. or Cryptogramma acrostichoides R. Br. ), or a dwarf-shrub tundra vegetation with scattered snow beds, dominated by Empetrum nigrum subsp. sibiricum (V.N. Vassil.) Kuvaev , Vaccinium uliginosum L. or Betula exilis Sukaczev. The microsites inhabited by T. atropurpureum typically represent open, sometimes mossy snow-bed patches, with Salix chamissonis Andersson at the type locality, and with a rich subalpine vegetation at the other site.

Another specimen examined:— RUSSIA. North Kamchatka, eastern coast, Karaginskiy District, Tymlat River basin, Yakotvon’ Mts. [ca. 59°39’49.7” N, 162°37’20” E, 320–330 m, slopes of a nameless mountain 825 m high, S of Mt. Roryranev], “ 824 m ”, 21 Aug 2011, O. Chernyagina ( KAM, no. det. 36882, paratype) .

Note:—The particulars and rectifications of both site descriptions were provided by the collector.

Figures

FIGURE 1. Geographical distribution of Taraxacum atropurpureum.

FIGURE 2. Taraxacum atropurpureum. General habit (KAM, no. det. 36882, paratype). Scale bar = 2 cm.

FIGURE 3. Taraxacum atropurpureum. Details of achenes (A, B. KAM, no. det. 36880) and involucre (C. KAM, no. det. 36880). Scale bars:A, C = 1 mm; B = 2 mm. The achene colour has a deeper purple hue when viewed in daylight.

FIGURE 4. Taraxacum atropurpureum in its natural habitat. A. The valley landscape of Tolyatovayam River, locus classicus (in the tent vicinity); B. T. atropurpureum at a mossy microsite among dwarf willows (Salix chamissonis), Tolyatovayam River; C. T. atropurpureum at the Yakotvon’ locality (note the conspicuously pruinose involucre and perfectly tubular, deep yellow ligules); D. T. atropurpureum at the type locality (Tolyatovayam River); E. Landscape below the Yakotvon’ Mts., the paratype locality (the exact site is marked with a pink dot). Photographed by O. Chernyagina, 2011.