Taraxacum rufum Dahlstedt (1930: 228)

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 : 94-95

37. Taraxacum rufum Dahlstedt (1930: 228)

Type:—[ RUSSIA, Kamchatka] Kamtchatka, Korjatskaja volcano, 14 Aug 1928, W. Eyerdam ( S 13-8868 !, syntype; S 11-21382 !, syntype; LE, no. det. 6036, syntype) .

Etymology:—Red, carroty, gingery.

Plants relatively robust, to ca. 15 cm tall. Petiole light green, unwinged, tunic absent. Leaves mid-green to light green, subglabrous to glabrous, linear-oblong to linear oblanceolate in outline, ca. 7–10 × 1.0– 1.7 cm, pinnatisect, with 3–5 pairs of narrowly triangular, recurved to subhamate, acute lateral segments, distal margin most often with a single lobule, entire in the most distal segments, straight of subconvex, proximal margin ± straight, usually entire; terminal segment ± triangular to almost tripartite with acute terminal and basal lobules; interlobes narrow, entire or with a single tooth or lobule. Scapes sparsely arachnoid. Capitulum not available. Involucre blackish green, ± rounded at base. Outer phyllaries ca. 12–14, ± appressed, narrowly ovate to ovate-lanceolate, ca. 6–7 × 2.2–2.7 mm, blackish green in the broad middle zone, with a gradual transition in a slightly paler submarginal zone, border not distinct, pale greenish, narrow, visible in basal part of some phyllaries, margin ± glabrous, apex with black cornicles or horns; inner phyllaries probably 12–14 mm long, corniculate. Stigmas discoloured. Pollen probably present. Achenes red-brown, ca. 4.3–4.5 × 1.0– 1.3 mm, body densely spinulose and squamulose in upper 1/3, subgradually narrowing into a thick subcylindrical cone, usually 0.8–0.9 mm long, 0.35–0.50 mm thick at base, ca. 0.3–0.4 mm distally; beak ± thin, ca. 8 mm long or longer at full maturity, pappus ± yellowish white, ca. 5.5–6.0 mm long. – Fig. 63 .

Diagnostic notes:— Taraxacum rufum is based on a rather late gathering. In the leaf shape and features of achenes, it is similar to T. stepanovae but differs in the shape and coloration of outer phyllaries. The possible difference in flower colour cannot be evaluated with certainty (flowers lacking in the original material of T. rufum ; the remnants of florets in LE, no. det. 6036, seem to be yellow).

Distribution:—Known from the southern Kamchatka (Koryakskaya Sopka, type gathering), and from Mil’kovskiy District in Central Kamchatka.

Specimens examined:—[ RUSSIA, Kamchatskaya Oblast] Central Kamchatka, Mil’kovskiy District, Nikolka , an east-exposed tundra slope, ca. 1150 m, 15 Aug 1987, V. V. Yakubov ( KAM, no. det. 36846) .

Figures

FIGURE 63. Taraxacum rufum. General habit and a detail of achenes (LE, no. det. 6036, syntype).