Taraxacum lauriferorum Kirschner & Štěpánek, 2025

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 : 31-33

7. Taraxacum lauriferorum Kirschner & Štěpánek , sp. nov.

Type:—[ RUSSIA, Kamchatka] Kamchatskyy krai, Bystrinskiy raion, k jugu ot vulkana Ichinskaya Sopka , dolina r. Ketachan 1-yy [Bystrinskiy District, south of the Ichinskaya Volkano, valley of Ketachan the 1 st River], 55°27.887’N, 157°44.583’E, luzhaika u inspektorskogo domika, 582 m, 12 Aug 2017, V. V. Buryy T064 ( PRA, no. det. 36920, holotype) .

Etymology:—Of people bearing laurel wreaths.

Diagnosis:—Species ex affinitate Taraxaci macroceratis, foliis laete viridibus glaberrimis, scapis dense arachnoideis, phyllariis exterioribus laxe adpressis vel erecto-patentibus, late et conspicue albomarginatis apice corniculatis, acheniis ± angustis corpore sparse spinuloso-squamuloso in pyramidem subcylindricam, saepissime 1.0- 1.1 mm longam persensim transeunte notabilis.

Plants medium-sized, sometimes slender, usually 15–23 cm tall. Plant base without tunic, subglabrous among petiole bases; petiole narrowly winged in outer and middle leaves, ± unwinged in inner ones, suffused pink or pale purplish. Leaves vivid mid-green to ± light green, usually ± glabrous, occasionally with very sparsely scattered short arachnoid hairs, narrowly oblong-oblanceolate in outline, usually 9–15 × 1.0–2.5 (–3.0) cm, sometimes ± undivided and remotely sinuate-dentate, mostly pinnatisect; terminal segment relatively small, ± deltoid-triangular, margins ± straight, entire, basal lobules ± patent, less foten subrecurved; lateral segments in 3–4 pairs, triangular, narrowly triangular or triangular-deltoid, subrecurved to patent, distal margin usually subconvex or subsigmoid, often straight, rarely subconcave, usually entire, sometimes with a single little tooth, proximal margin ± straight, ± entire; interlobes distinct, green, entire or minutely denticulate; mid-vein usually pale green, sometimes slightly suffused pinkish. Scapes brownish green, later sometimes ± purplish, initially densely arachnoid, later sparsely so, ± equalling, later ± overtopping leaves. Capitulum golden yellow, usually 2–3 cm wide. Involucre ± olivaceous green to dark olivaceous, 8–9 mm wide and narrowly rounded to subobconical at base. Outer phyllaries (13) 14–15 (16), loosely appressed to erect-patent (forming a “star” around closed capitulum when viewed from above), subimbricate or not imbricate, ovate-lanceolate to narrowly lanceolate, usually 5.5–7.0 (–7.5) × 2.2–3.0 mm, surface deep greyish olivaceous-green to blackish olivaceous in the central part, rarely light olivaceous, the dark central band bordered by a light olivaceous-green zone ca. 0.5–0.8 mm wide, with a gradual transition into a whitish to whitish-membranous border 0.3–0.4 mm wide (when surface very dark, the border is limited to ca. 0.5 mm wide whitish zone), margins ± glabrous, apex blackish corniculate (sometimes suffused purple). Outer ligules flat to canaliculate, usually striped dark greenish grey-purple outside, teeth blackish, inner ligule teeth dirty yellow to greyish. Pollen abundant, conspicuously irregular in size. Stigmas deep yellow, usually not discoloured, sometimes slightly discoloured (faintly suffused light purplish) or very light discoloured (pale greenish yellow). Achenes light greyish olivaceous-stramineous brown, 3.8–4.4 × 0.8–1.0 mm, body sparsely but regularly covered with spinules or thin squamules in upper 1/3–1/2, very gradually narrowing into a subcylindrical cone 0.9–1.3 mm long, ca. 0.35–0.40 mm thick at base, ca. 0.3 mm distally; beak thin, usually 10–12 mm long, pappus white, 6–7 mm long. – Agamospermous. – Fig. 14 , 15 .

Diagnostic notes:—There are several Arctic and Kamchatka species with yellow or almost yellow stigmas. The closest one to T. lauriferorum is T. macroceras . The latter primarily differs from our species in its short, broadly conical cone, thicker achenes, its leaf shape and posture and coloration of outer phyllaries.

Distribution and habitat:— Taraxacum lauriferorum is known from a series of gatherings in the central part of Kamchatka (Mil’kovskiy and Bystrinskiy districts). It is not a species of tundra, and occurs at elevations from 400 to 600 m.

Specimens examined:—[ RUSSIA, Central Kamchatka] Mil’kovskiy District, between Mil’kovo and Shanuch, 55°19.543’N 158°02.749’E, 410 m, 12 Jun 2015, V. V. Buryy T062 (herb. V. V. Buryy, no. det. 36922). – Bystrinskiy District , village of Esso, Sovkhoznaya Street, 55°55.600’N 158°42.740’E, 483 m, 2 Jun 2015, V. V. Buryy T043 & T044 (herb. V. V. Buryy, no. det. 36924); ibidem, V. V. Buryy T045 & T046 (herb. V. V. Buryy, no. det. 36926). – Bystrinskiy District , village of Esso, NW. margin of the village, 55°55.701’N 158°41.405’E, near R. Uksichan, 491 m, 4 Jun 2015, V. V. Buryy T048 & T050 (herb. V. V. Buryy, no. det. 36915) .

Species with white or yellowish white flowers

Figures

FIGURE 14. Taraxacum lauriferorum. The holotype. Photo M. Hladík.

FIGURE 15. Taraxacum lauriferorum. A, general habit (PRA, no. det. 36920, holotype); B, achenes (herb. V. V. Buryy, no. det. 36922). Scale bars:A = 5 cm; B = 1 mm.