Taraxacum sect. Erythrocarpa Handel-Mazzetti (1907

Štěpánek, Jan & Kirschner, Jan, 2022, Taraxacum sect. Erythrocarpa in Europe in the Alps and eastwards: A revision of a precursor group of relicts, Phytotaxa 536 (1), pp. 7-52 : 9

Taraxacum sect. Erythrocarpa Handel-Mazzetti (1907 : xi).

Type (designated by Doll 1973: 2):— Taraxacum calocephalum Handel-Mazzetti (1907: 106) .

Plants usually medium-sized, not slender, of a ± robust habit, base with a tunic or with a few old petioles, or without tunic. Petiole winged, usually broadly winged in outer and middle leaves, not winged in later, inner leaves; leaf blade pinnatisect; lateral lobes few to numerous, usually triangular to narrowly triangular, patent to ± recurved, margin entire or (usually on interlobes) often dentate or lobulate. Capitulum usually (2.5–) 3–3.5 (–4) cm wide. Outer phyllaries usually 12–20, lanceolate to broadly ovate, long, often imbricate, appressed, loosely appressed, or less often arcuaterecurved, usually distinctly broadly or narrowly bordered, apex flat to corniculate. Ligules yellow; floret tube glabrous. Achene red, reddish brown, brown, castaneous, cinnamon or light greyish stramineous-brown, usually 4.3–5.5 mm long; body usually densely spinulose above, usually subabruptly to subgradually narrowing into a distinct cylindric (0.5–) 1–1.5 mm cone, spinules long and thin; beak usually 0.8–1.3 cm. Pappus ± white.

Members of T. sect. Erythrocarpa are agamospermous, with a single exception, T. pindicola . Within the distribution area of T. pindicola or in its vicinity, the variation pattern of T. sect. Erythrocarpa follows the geographical parthenogenesis model (Hörandl 2006), and several agamospermous species are morphologically close to the variable sexual taxon.

About 45 species are known to belong to T. sect. Erythrocarpa , occurring in the northern Mediterranean and Irano-Turanian regions, including Spain, Italy, Balkan Peninsula, the Black Sea region, Turkey and Iran, and occasionally are found outside that area (the Western Carpathians, the Caucasus, Iraq, Afghanistan, China). The section, both morphologically and on the basis of molecular analyses, is close to T. sect. Erythrosperma (smaller achenes, outer phyllaries usually not appressed, without border or with a less distinct border, leaf shape more complicated). Another similar but geographically remote group is T. sect. Dissecta van Soest (1966: 377 , for a more detailed information, see Ge et al. 2011), and there are also morphological links to T. sect. Scariosa [with T. panhellenicum as the species closest to intersectional intermediates, e.g., T. graecum Dahlstedt (1926: 6) ].

Since 1985, we re-defined T. sect. Obliqua ( Dahlstedt 1909: 172) Dahlstedt (1921: 37) , another related and similar group, originally including only two agamospermous species, T. obliquum ( Fries 1814: 14) Dahlstedt (1905: 152 & 164) and T. platyglossum Raunkiaer (1906: 256) but now understood as a group centered around the sexual T. pyrenaicum Reuter (1861: 4) and covering not only the two coastal species but also a number of similar plants from the Western Alps and adjacent areas, mainly in France. Thus, T. aquilonare Hand. -Mazz. in Dalla-Torre & Sarnthein (1912: 687), included in T. sect. Erythrocarpa by us in 1985 ( Kirschner & Štěpánek 1985), is now treated as a marginal member of T. sect. Obliqua .

A morphological comparison of T. sect. Erythrocarpa with similar sections is given in Tab. 1 .

While the species of T. sect. Erythrosperma and T. sect. Dissecta are mostly widespread and grow at lower elevations, often with an ability to spread to sites influenced by human activities, the European T. sect. Erythrocarpa is characterized by the majority of species confined to relictual mountain rocky sites, often calcareous cliffs, mountain summits, usually at subalpine to alpine sites. Many species occupy only a limited number of localities and represent local endemics or narrow endemics; they do not spread outside the relict sites.