Taraxacum roseiflos Kirschner & Štěpánek, 2017

Kirschner, Jan & Štěpánek, Jan, 2017, A revision of Taraxacum sect. Atrata, a dandelion group centred in the Middle Asia, and the problem of Taraxacum brevirostre, Phytotaxa 305 (4), pp. 225-261 : 249-250

14. Taraxacum roseiflos Kirschner & Štěpánek , sp. nova.

Type: — KYRGYZSTAN. Ysyk Kol [Issik-kul] Province, Ak-Su Region, Terskey Ala-Too, valley of Saryzhaz River, southern slopes at 3600 m, in the vicinity of 42°25‘44“N, 79°35‘10“E, 2014, I. Ulbrichová s.n. Cultivated from achenes under no. JK6962A ( PRA, no. det. 28146, holotype).

Diagnosis: — Plantae graciles foliis et scapis glaberrimis, phyllariis exterioribus imbricatis, ovatis vel late ovatis late marginatis sparse ciliolatis, antheris polliniferis, stigmatibus obscuris, capitulis intense roseis purpurascentibus, acheniis laevibus rubro-badiis magnis, rostro brevi.

Description: —Plants small, usually to 10 cm tall. Petiole green, later midrib bordered purplish, narrow, unwinged, glabrous, plant base without remnants of old petioles. Leaves mid-green to vivid green, mid-vein green to bordered purplish, oblanceolate in outline, usually 3–7 × 1–1.5 cm, glabrous, outer leaves undivided, spathulate, usually with 1–2 pairs of short triangular teeth, later leaves with 1–2 pairs of patent, broadly deltoid entire lobes, inner leaves deeply divided into 1–2 pairs of patent, symmetrical deltoid segments to 6–7 mm long, terminal segment, when developed, ± triangular, obtuse to subacute, with basal lobules similar to lateral segments. Scapes brownish green, glabrous, overtopping leaves. Capitulum large, 3–5 cm wide. Involucre dark green, ± not pruinose, ca. 8–10 mm wide, rounded at base. Outer phyllaries (9) 10–11, imbricate, ovate to broadly ovate, usually 5–9 × 3–4.5 mm, ± appressed, blackish green, with a whitish to greenish-whitish border (0.2–) 0.4–0.5 (–0.7) mm wide, rarely border ± absent from some phyllaries, with subgradual transition into the middle part, margins sparsely minutely ciliate to ± glabrous, apex flat to callose; inner phyllaries to ca. 15 mm long, dark green, flat. Flower colour (in all florets) homogenously purplish deep pink, outer ligules flat, indistinctly striped light greyish purple outside, inner ligule teeth grey-purple. Stigmas dark green, outside with pale pubescence. Anthers polliniferous (sparsely so in inner florets, in some florets pollen may be absent); pollen grains irregular in size. Achenes red-brown, 5.8–6.1 × 1.1–1.2 mm, body smooth or with a few minute tubercles above, cone not developed, body part above tubercles thick, ca. 0.5–0.7 mm long, with a gradual transition into beak; beak easily breaking off, thickened (0.25–0.35 mm), usually 3.5–4 mm long. Pappus ± white, ca 5–5.5 mm long.—Agamospermous.— Fig. 18A , 20.

Comparison with other taxa: — Taraxacum roseiflos is an extremely distinctive species characterized by red-brown achenes (the only case in this section), ovate and conspicuously bordered imbricate outer phyllaries, deep pink to pink purplish flowers (similar to those of T. lilacinum ) and dark stigmas. Its leaf shape pattern also approaches T. lilacinum because the majority of leaves are spathulate, undivided. However, a certain proportion of leaves is lobed, unlike those of T. lilacinum . Known from the type locality ( Fig. 22 ).

Specimens examined: — KYRGYZSTAN. Ysyk Kol [Issik-kul] Province, Ak-Su Region, Terskey Ala-Too, valley of Saryzhaz River, southern slopes at 3600 m, in the vicinity of 42°25‘44“N, 79°35‘10“E, 2014, I. Ulbrichová s.n. Cultivated from achenes under no. JK6962A (isotypi: PRA, no. det. 28147, 28148, 28149).

Figures

FIGURE 18. Achenes of (A) T. roseiflos (PRA, no. det. 28146) and (B) T. roseolum (PRA, no. det. 28150). Scale bar = 1 mm.

FIGURE 22. Distribution ranges of T. atrochlorinum (square), T. dzhungaricola (triangle), and T. roseiflos (circle).