Taraxacum assemanii, C. I. Blanche ex Boissier, 1875

Kirschner, Jan, Štěpánek, Jan, Doostmohammadi, Moslem & Zeisek, Vojtěch, 2021, Taraxacum assemanii represents a new section: A revision of the misinterpreted Taraxacum primigenium, and the elucidation of the enigmatic Taraxacum section Primigenia (Compositae, Crepidinae), Phytotaxa 520 (2), pp. 117-136 : 125-126

Taraxacum assemanii , a remarkable separate species

After having characterized T. primigenium , we can return to T. assemanii . The achene attributes of the latter species are rarely found in Taraxacum ( Fig. 6 ). The cone is hardly discernible and it gradually and indistinctly changes into a short, thickened rostriform part of the achene; even the fine microsculpture of the achene and cone body gradually gets thinner distally, and the distal rostriform part is smooth. A similar character of the achene body/beak transition is found, for instance, in T. glaciale . Outer phyllaries of T. assemanii are close to those of T. cylleneum but more numerous, and not far from the involucre of T. primigenium s. str. We conclude that T. assemanii is a remarkable species, in many respects very different form T. primigenium .

Sectional position of Taraxacum assemanii :—There are several Taraxacum species endemic to the eastern part of the Mediterranean and occupying quite isolated positions, both morphologically and from the viewpoint of Taraxacum evolution. Some of them represent isolated sexuals with a group of closely related agamospermous species, such as T. farinosum , a member of T. sect. Sonchidium , or T. bithynicum Candolle (1838: 149) [with the very similar T. pseudobithynicum Gürdal et al. (2018: 206) ], for the time being without sectional classification, others, also sexual, are extremely distinctive, without known close relatives, and are recognized as separate, monotypic sections, viz. T. (Glacialia) glaciale or T. (Echinulata) mirabile Wagenitz (1962: 279) , see Kirschner et al. (2021). Taraxacum assemanii is a sexual species with several very distinctive characters of achenes. The rare character states include fusiform achene shape, the absent or almost absent achene body spinulosity, usually ± indistinguishable cone and beak forming a “rostriform” structure with its distal part thick, the microscopic sculpturing of achenes gradually getting thinner distally, and often slightly brownish, relatively short pappus. We can add the low number of appressed outer phyllaries (without horns or cornicles), and yellow stigmas.

Taraxacum assemanii substantially differs from T. sect. Epyramidata ( Orazova 1969: 38) Kirschner & Štěpánek in Kirschner et al. (2020: 138) in the glabrous or sparsely ciliate outer phyllaries, the absence of horns on phyllaries, and the character of achene body/beak transition. Taraxacum sect. Glacialia Handel-Mazzetti (1907: 15) , with T. glaciale as the only representative, is characterized by a totally different involucre. The features of achenes exclude the placement of T. assemanii in T. sect. Piesis, and, as demonstrated in the present paper, the name Taraxacum sect. Primigenia cannot be used to accommodate T. assemanii , either, in spite of the original sectional description including features of the latter species. There is a superficial similarity between T. assemanii and T. sect. Squamulosa Kirschner & Štěpánek (2017: 7) ; the latter is characterized by achenes squamulose below the clearly differentiated cone, the cone/beak transition very distinct, and by a relatively thin beak, i.e. features very different from those of T. assemanii . The distinctive nature of T. assemanii therefore deserves an inclusion in a new, monotypic section.

Figures

FIGURE 6. Taraxacum assemanii. Achenes: A, Khan Sannine (G, no. det. 22576). B, Aïn Sannin (G, no. det. 22579). C, Hasroun (G- BOISS, no. det. 18810). A, B, C—Lebanon. D, Metdesis (G-BOISS, no. det. 18812, lectotype). E, Boulgarmaden (G, no. det. 30405). F, Anemas (G-BOISS, no. det. 18803). Flower head: G, Metdesis (G-BOISS, no. det. 18812, lectotype). D, E, F, G—Turkey. Scale bars = 1 mm.