Taraxacum kuvajevii Tzvelev

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 : 100-102

41. Taraxacum kuvajevii Tzvelev in Tzvelev & Yurtzev (1984: 196) Type:—[ RUSSIA, Sakha Republic] Yakutia, Lenskiy r-n, k-z “Dvigateľ”, melkozlakovo-klevernyy vygon po II poime Leny za rechkoi

Mukhtuikoi, 0.5 km vyshe okrainy poselka Mukhtuya [Sakha Republic, Lensky District, Lensk, ca. 60° 43’ N, 114° 54’ E], 25 Jul

1953, V. Kuvaev & A. Petrov 58/11 ( LE, no. det. 6046, holotype). Etymology:— Named after V. B. Kuvaev (1918—2009, Владимир Борисович Куваев), a specialist in the flora of the Russian Arctic .

Plants relatively small, usually 6–8 cm, sometimes to 13 cm tall. Petiole narrow to very narrowly winged, subglabrous, purplish. Leaves greyish light green with ± purplish mid-vein, subglabrous, broadly oblaceolate in outline, usually 6–9 × (1.0–) 1.5–2.5 (–3.0) cm, deeply pinnatisect (late leaves less deeply divided), usually with 4–5 pairs of linear or linear-lingulate, patent, entire lateral segments, usually 8–20 × 1.5–3.0 mm, terminal segment tripartite with linear parts, interlobes usually very narrow, usually filiform-dentate or with linear lobules. Scapes brownish green, often suffused purple, sparsely arachnoid, ± equalling leaves. Capitulum light yellow, ca. 2–2.5 cm wide. Involucre light green, ca. 6–7 mm wide and subobconical at base. Outer phyllaries ca. 11–13, loosely appressed, not imbricate, linear to linear-triangular, usually 5–8 × 0.8–1.7 mm (length including horns), light greenish, with a whitish-membranous border ca. 0.3 mm wide, margins ± glabrous, apex with light green, thin, acute, perpendicular to suberect horns ca. 3–4 mm long, ca. 0.5–0.8 mm thick near the base; inner phyllaries light green, ca. 11–12 mm long, with thin horns. Outer ligules flat, faintly striped grey outside, teeth dirty yellow. Stigmas very light, pale yellowish, dirty yellowish or very pale greenish yellow. Pollen present, pollen grains irregular in size. Achenes red-brown, 3.3–3.7 mm long, body ± densely spinulose in upper 1/3, subabruptly narrowing in a subcylindrical cone 0.5–0.7 mm long; beak ca. 8–9 mm long, pappus white, ca. 6–6.5 mm long. – 2n=24, fide Zhukova in Tzvelev & Yurtzev 1984:197. – Agamospermous. – Fig. 69 .

Diagnostic notes:—In spite of a rather late type gathering, T. kuvajevii is enormously distinct in having very long, thin horns to ± linear outer phyllaries, pale stigmas and red-brown fruits. This character combination is unique among dandelions.

Distribution:—Known from the type locality in the Sakha Republic (Lensk). In Tzvelev & Yurtsev (1984) and in Perfil’eva et al. (1987), several additional localities from central Sakha are listed (LE, n. v.). For one of the specimens, the chromosome number 2n = 24 was reported in the former work.

Note:—There is another species with very long, greenish, thin horns on the outer phyllaries, and deeply dissected leaves with narrow, linear, patent lateral segments, Taraxacum pospelovii Tzvelev & Pospelova (2015: 224) . It has light greyish stramineous-brown achenes. We have seen the type specimen (as a photograph); this species requires further study.

A representative of the Taraxacum lacerum group in Kamchatka

The group of T. lacerum Greene (1901: 230) was studied in detail by Haglund (1943, 1946, 1948 and 1949). Haglund (1948) concluded that the group consists of several taxa, and ( Haglund 1949) described several of them, most importantly, T. sublacerum Haglund (1949: 112 , figs. 4 and 5b). Other taxa considered include T. carthamopsis Porsild (1939: 32) , T. ochraceum Haglund (1946: 351) , T. mutilum Greene (1901: 232) , T. norvegicum (Dahlst.) Dahlst. and T. groenlandicum Dahlstedt (1906: 23) , the latter two equated with T. lacerum by Haglund (1948).

In the new material from Kamchatka, we found two specimens clearly belonging to this group, previously unknown from the continental Far East. The absence of pollen, usually subtubular or at least canaliculate ligules, light green, conspicuously bordered outer phyllaries were the main characters pointing to T. sublacerum . The only feature deviating from the known morphological pattern of T. sublacerum is the purplish coloration of petioles, which we tentatively ascribe to the plasticity under varied ecological conditions.

Figures

FIGURE 69. Taraxacum kuvajevii. Involucre; note the long, relatively thin horns (LE, no. det. 6046). Scale bar = 5 mm.