Taraxacum albescens Dahlstedt (1926b: 14)

Kirschner, Jan, Štěpánek, Jan & Buryy, Vladimir V., 2025, Towards a revision of Taraxacum sect. Borealia (Compositae, Crepidinae) in Siberia and the continental Far East, with special reference to the dandelions of the Altai and Kamchatka, Phytotaxa 679 (1), pp. 1-147 : 36-37

10. Taraxacum albescens Dahlstedt (1926b: 14)

Type:—[ RUSSIA, Kamchatka] [transcribed label] Kamtchatka, in alpibus “Ganalski Ostraki” [a mountain range of Ганальские Bостряки, Ganalskie Vostryaki, in S. Kamchatka], П. Т. НОВОгРаБЛенОВ, no. 660 [on the original little label], 18 Jul 1924, P. T. Novograblenof ( S 05-7617 !, holotype) . - Ganalskie Vostryaki , na vershine u “Vostryakov”, 18 Jul 1924, P. T. Novograblenov 660 ( LE, no. det. 7927, 17101, isotypes) .

Etymology:—Becoming white, whitening.

Plants small, to 4.5–5.5 cm tall, of ± robust appearance. Petiole narrowly winged, subglabrous, purplish, tunic absent. Leaves deep green to dark green, subglabrous, ± linear-oblong in outline, usually 3–4.5 (–5) × 0.6–1.4 cm, pinnatifid, with 3–5 pairs of ± approximated, regularly arranged, narrowly deltoid to narrowly deltoid-triangular, seldom deltoidsubhamate, subacute, entire lateral segments; terminal segment helmet-shaped-triangular, subobtuse to subacute, entire, with ± patent basal lobules; interloes short and broad, often with raised margin, entire or with a single tooth; mid-vein purplish. Scapes brownish green, usually suffused purplish, initially arachnoid, later sparsely so, subequalling leaves. Capitulum with almost white or slightly yellowish white outer rows of florets, pale (whitish-)yellowish inner florets, ca. 2–3 cm wide. Involucre blackish green, ca. 7.5–9 mm wide and rounded at base. Outer phyllaries ca. 9–12, appressed, imbricate, ovate to ovate-lanceolate, usually 6.0–6.5 (–7.5) × (2.0–) 2.2–3.0 (–3.3) mm, surface mostly black-green, distally or wholly ± suffused purplish, with a ± gradual transition into a whitish-membranous (and purplish) border ca. 0.3–0.5 (–0.6) mm wide, margin ± glabrous, apex darker corniculate, with cornicles ca. 0.5 mm long. Outer ligules ± white, usually faintly striped pinkish grey or grey outside, teeth grey-purplish, inner ligule teeth dirty purplish. Stigmas discoloured. Pollen present, pollen grains irregular in size. Achenes light red-cinnamon when unripe, later red-brown to dark reddish brown, ca. 4.2–4.7 × 1.0– 1.2 mm, body subsparsely squamulose and spinulose in upper 1/3, gradually narrowing into a subconical to subcylindrical cone 0.8–0.9 mm long; beak 7–9 mm, pappus ± white, ca. 5.5 mm long. – Agamospermous. – Fig. 19 , 20 .

Diagnostic notes:—The peculiar floret colour (from almost white outer ligules to yellowish central ones) and the leaf shape are diagnostic. A detailed comparison with T. stepanovae is needed because of a rather incomplete material of T. albescens and a high overall similarity. Winged petioles, relatively broadly bordered and clearly corniculate outer phyllaries point to T. sect. Borealia. Taraxacum albescens , nevertheless, may represent an intermediate form with links to T. sect. Arctica.

Distribution:—Known from a locality in the southern part of Vostochnyi Range in southern Kamchatka, in Ganal’skiy Range (Ganal’skie Vostryaki), probably at the elevations between 1500 and 2000 m, and another site in the Bystrinskiy District of Kamchatka. Reported from numerous localities in Kamchatka ( Tzvelev 1992) but the specimens so identified that were examined by us do not belong to T. albescens .

Specimens examined:— RUSSIA. Kamchatka, Bystrinskiy District, SW. of Ichinskaya Sopka volcano, vicinity of Dva Brata , upper stream of R. Rassoshina , 55°36.127’N, 157°30.046’E, 1396 m, 8 Jul 2017, V. V. Buryy & A. Lace T109 , T111 & T112 (herb. V. V. Buryy, no. det. 36903) .

Figures

FIGURE 19. Taraxacum albescens. General habit (A, S 05-7617; B, LE, no. det. 7927).

FIGURE 20. Taraxacum albescens. A, a detail of capitulum; B, general habit (both photographed by V. Buryy, locality of no. det. 36903); C, achenes (herb. V. Buryy, no. det. 36903, note the paler colour of an unripe achene on the left).