Taraxacum annetteae and Taraxacum croaticum, found in the N coastal part of Croatia, are described as species new to science and illustrated, and their known distributions are given. Both species belong to T. sect. Erythrosperma.
Version of record first published online on 28 July 2016 ahead of inclusion in August 2016 issue.
The exploration of the genus Taraxacum in Croatia by the present author was initiated by W. Rottensteiner (former W. Starmühler, Austria, Graz), who is studying the flora of the peninsula of Istria and the islands of the bay of Kvarner for the recently published Exkursionsflora für Istrien (Rottensteiner 2014). In the course of the preparation of this Flora, the present author discovered some hitherto unknown species belonging to T. sect. Erythrosperma (H. Lindb.) Dahlst. In two previous papers (Uhlemann 2007, 2010) the author described three new species of this section. Two further species are described as new to science in the present paper. Both species are classified in T. sect. Erythrosperma due to their delicate habit, outer involucral bracts with a small white border and tips with corniculations below the apex, and brown achenes with long cylindrical pyramides.
Holotype: Croatia, bay of Kvarner, isle of Krk, SE part of the island, pass at entrance to Baška valley, c. 50 m above monument, roadside, 10 Apr 2007, I. Uhlemann (B 10 0673409; isotypes: PRA, S, herb. Uhlemann).
Planta mediocriter (5-)10–15 cm alta, gracilis. Folia canoviridia, subglabra, immaculata. Petioli inalati, angusti, lucide rubropurpurei. Nervus medianus sordide viridis. Lamina foliorum distincte lobata; lobi laterales 4 vel 5 (vel 6) utrimque, lati vel anguste deltoidei, patentes, subobtusi vel lingulati, in marginibus distalibus uno dente magno et lato instructis, in marginibus proximalibus integri vel uno dente minuto instructis; lobus terminalis parvus, triangularis, lobulo apicali elongato usque linguiforme protracto; interlobia bene evoluta, piceata, saepe dentata. Scapi superne valde, ceterum parce araneosi, brunneo-virides. Involucrum olivaceo-viride, leviter pruinosum. Squamae exteriores numero 16–20, supra valde colore rubro-violaceo tinctae, subtus fusco-virides, unguiformis, recurvatae, lanceolatae, 8–9 mm longae, 2–2.5(-3)mm latae, anguste albido marginatae, sub apice minute corniculatae. Calathium 2–2.5(–3) cm diametro, luteum, radians. Ligulae marginales planae, subtus stria canoviolacea instructae. Antherae polliniferae, granis pollinum diametro variabili. Stylus superne obscure canoviridis. Achenium laete brunneum, 2.5–2.6 mm longum (pyramide exclusa), superne spinulosum, spinulis validis, ceterum squamulosum vel rugosum, in pyramidem cylindricam, 0.8–0.9 mm longam abrupte abiens, rostrum 8–9 mm longum. Pappus albus.
Description — Herbs delicate, (5-) 10–15 cm tall. Leaves greyish green; petiole light purple, thin, unwinged; leaf blade distinctly lobed, with 4 or 5 (or 6) pairs of triangular lateral lobes; midrib brownish green (dirty green); lateral lobes patent, usually with a distinct tooth on proximal and distal margin, apex ± blunt or lingulate; interlobes tar-coloured, well differentiated, dentate; terminal lobe triangular, apex shortly lingulate. Scape hairy below involucre; involucre olive-green, somewhat pruinose at base; outer bracts intensely purple-coloured, lanceolate, arcuate-reflexed with apex pointing back to scape (claw-like), 8–9 mm long, 2–2.5(-3) mm wide, with small white border and corniculations below apex; calathium 2–2.5(-3) cm in diam.; corolla pure yellow but outermost ligules striped greyish violet abaxially; pollen present, variable in diameter; styles dark greyish green. Achenes pale brown (without red colour); achene body (without cone) 2.5–2.6 mm long, with large spines in distal part; cone cylindric, 0.8–0.9 mm long; rostrum 8–9 mm long; pappus white.
Distribution — Taraxacum annetteae is an extremely rare species. Up to now it is known only from two remote localities in Croatia, where it forms populations with more than 100 individuals (Fig. 7).
Affinities — The most striking diagnostic feature of Taraxacum annetteae is the intense purple coloration (even in shady places) of the arcuate-reflexed outer bracts with their tips pointing back to the scape. Each of these outer bract character states (colour and position) is rare in T. sect. Erythrosperma, but the combination is unique. Furthermore, the species is characterized by light purple petioles, shortly triangular, blunt or sometimes lingulate lateral leaf lobes with a distinct large tooth on the distal margin and a less distinct tooth on the proximal margin, tar-coloured interlobes, pollen-producing anthers, dark greyish green styles and small, pale brown achenes with large spines in the distal part.
With regard to the arcuate-reflexed outer bract position, Taraxacum annetteae resembles T. lacistophylloides Dahlst. (1933), but the latter species has light green outer bracts, a more robust habit, grey achenes and a completely deviating shape of lateral leaf lobes.
In T. purpureocornutum Soest (1957), a rare and probably endemic species from Corsica (Štěpánek & Kirschner 2012), only the outermost outer bracts are arcuate-reflexed, whereas the inner ones are arcuate or patent. Moreover, this species has a completely deviating leaf shape, pinkish grey-green outer bracts, produces no pollen and has larger achenes with a longer pyramid than T. annetteae.
Only a few other species of Taraxacum sect. Erythrosperma have intensely purple-coloured outer bracts, such as T. pupureomarginatum Soest (1964), but this species differs from T. annetteae in having irregularly arcuate outer bracts, yellow-green styles and larger, grey achenes. Also the C and N European T. bellicum Sonck (1983) has an intense purple outer bract coloration, but in contrast red-brown achenes c. 3 mm long with a cone 1.3–1.5 mm long, triangular, acuminate lateral leaf lobes and a long sagittate, incised terminal leaf lobe.
With regard to leaf shape, Taraxacum lingulilobum Sonck (1984), described from Greece and also found in Bulgaria (Štěpánek & Kirschner 2014), is similar, but this species has green or very faintly dirty violet petioles, dark green outer bracts and red-brown achenes more than 3 mm long with a cone c. 1 mm long.
The pale brown achenes of Taraxacum annetteae resemble those of T. plumbeum Dahlst (1911) with respect to their coloration, but the latter species has a completely deviating leaf shape and green, erect outer bracts with recurved tips.
Eponymy — The epithet is dedicated to my wife, Annette, who has patiently supported and suffered my taxonomic studies in Taraxacum over a period of more than two decades.
Additional specimens seen — Croatia: Dalmatia, Starigrad, Velika Paklenica, c. 2 km oberhalb des Parkeingangs, Wegrand, zahlreich, 15 Apr 2009, I. Uhlemann (B, herb. Uhlemann).
Holotype: Croatia, bay of Kvarner, isle of Cres, Valun, crossroads of a footpath close to the beach at W outskirts of village, semi-shady below trees, 25 Mar 2008, I. Uhlemann (B 10 0673408; isotypes: PRA, S, herb. Uhlemann).
Planta mediocriter 10–15(-20) cm alta, gracilis. Folia laete canoviridia, subglabra, immaculata. Petioli inalati, angusti, rubropurpurei. Nervus medianus sordide viridis. Lamina foliorum distincte lobata; lobi laterales 3 vel 4(-6) utrimque, lati vel anguste deltoidei, subhamati vel recurvi, acuti, in marginibus distalibus et marginibus proximalibus integri vel dente minuto instructi; lobus terminalis sagittatus, lobulo apicali saepe elongato usque linguiforme protracto; interlobia bene evoluta, viridia, saepe dentata. Scapi glabrus vel sparse araneosi, brunneo-virides. Involucrum glauco-viride, pruinosum. Squamae exteriores numero (11 vel) 12 vel 13(-15), erectae, late lanceolatae, 7–9 mm longae, (2-)3–4 mm latae, anguste albido vel roseo-marginatae, sub apice minute corniculatae. Calathium 2–2.5 cm diametro, luteum, radians. Ligulae marginales planae, subtus stria canoviolacea instructae. Antherae polline carentes. Stylus superne (obscure) canoviridis vel siccis nigris. Achenium laete brunneum, 3–3.1 mm longum (pyramide exclusa), superne dense spinulosum, ceterum squamulosum vel rugosum, in pyramidem cylindricam, 1–1.2 mm longam abrupte abiens, rostrum 6–8 mm longum. Pappus albus.
Description — Herbs delicate, 10–15(-20) cm tall. Leaves greyish green; petiole purple-red, thin, unwinged; leaf blade distinctly lobed with 3 or 4(-6) pairs of broadly or narrowly triangular lateral lobes; midrib brownish green (dirty green); lateral lobes recurved to nearly hamate, usually entire on proximal and distal margin; interlobes green, well differentiated, dentate; terminal lobe triangular or sagittate, apex lingulate. Scape glabrous or very sparsely aranose; involucre glaucous, pruinose; outer bracts (11 or) 12 or 13(-15), broadly lanceolate, erect, 7–9 mm long, (2-)3–4 mm wide, with a pink or white border, corniculate below apex; calathium c. 20–25 mm in diam.; corolla pure yellow but outermost ligules striped greyish violet abaxially; pollen absent; styles (dark) grey-green or in dried condition blackish. Achenes pale brown (without red colour); achene body (without cone) 3–3.1 mm long; cone cylindric, 1–1.2 mm long; rostrum 6–8 mm long; pappus white.
Distribution — Taraxacum croaticum is so far known from Istria and the islands of Cres, Losinj, Pag and Rab in the bay of Kvarner in Croatia, and from a single, remote locality in Starigrad, Dalmatia (Fig. 7).
Affinities — Taraxacum croaticum is mainly recognized by its flowers lacking pollen, greyish to blackish styles, pale brown achenes, few erect outer bracts, thin, unwinged and purple-red petioles, a characteristic leaflobation with more or less entire and hamate lateral lobes and long interlobes.
With regard to leaf shape this species is related to other species in Taraxacum sect. Erythrosperma with more or less hamate lateral lobes, such as T. lambinonii Soest (1961), which is distinguished by strongly hamate leaf lobes, shorter interlobes, presence of pollen and (greyish)brown achenes; and furthermore T. aquitanum Hofstra (1988), with strongly hamate leaf lobes, shorter interlobes, presence of pollen, erect to patent outer bracts and red-brown achenes with a shorter, 0.7–0.8 mm long cone.
Taraxacum croaticum should be also compared with the well-known species T. parnassicum Dahlst. (1926) [= T. silesiacum Dahlst. ex G. E. Haglund (1938) = T. praegracilens Sonck (1989), nom. nov. for T. pseudogracilens Sonck (1988)], common in C Europe, ranging to the Mediterranean and scattered in N Croatia, which resembles the first in its flowers lacking pollen, dark styles and more or less hamate to recurved lateral lobes on the outer leaves. Some modifications of T. parnassicum, for instance those pictured under the name T. pseudogracilens (Sonck 1988: 77, fig. 3A, C), tend with regard to leaf shape to T. croaticum; but, in contrast, T. parnassicum has more numerous outer bracts, which are patent or erect with recurved tips and a deviating leaf lobation (shorter and patent lateral lobes on the inner leaves, which tend to stand closer in the distal part of the leaf, and short interlobes).
Taraxacum croaticum also resembles to T. plumbeum Dahlst (1911) with regard to the pale brown achenes and leaf lobation, but the latter species has aranose leaves, short, hamate to recurved lateral leaf lobes, which sometimes (mainly on the inner leaves) become long and tapering, shorter interlobes and pollen-producing anthers.
Taraxacum taraxacoides (Hoppe & Hornschuch) Willkomm (Hoppe & Hornschuch 1818; Willkomm & Lange 1865), the most frequent species of T. sect. Erythrosperma in N Croatia, is distinguished from T. croaticum by smaller and more numerous horizontal lateral leaf lobes, outer bracts 2–3 mm wide (but erect as in T. croaticum) and red-brown achenes.
Superficially considered, Taraxacum croaticum is similar to some modifications of T. erythrospermum Andrz. (in Besser 1822), but this species has a sexual mode of reproduction, regular pollen grains of nearly the same size, yellow or greenish yellow styles, redbrown achenes and an extraordinary variability in leaf shape.
Etymology — The specific epithet alludes to the country where this species occurs.
Additional specimens seen — Croatia: Istria, Ostküste, Opatija, Vebrinaciin johtavan polun varressa kaupungin yläpuolella, 7 May 1988, J. Räsänen (herb. Räsänen, herb. Uhlemann); Westküste, nördlich Peroj, Trift, Garrigue, 52 m, 14 Apr 2012, K. G. Bernhardt (KL). Cres, nordwestlicher Teil des Insel, Dragozetici, Straßenrand im Dorf, 4 Apr 2002, I. Uhlemann (herb. Uhlemann); Valun, Serpentinstraße oberhalb des Ortes, 25 Mar 2008, I. Uhlemann (B, herb. Uhlemann); Südwestküste, Ustrine, Ortslage, Straßenrand, 25 Mar 2008, I. Uhlemann (herb. Uhlemann). Losinj, Umgebung von Mali Losinj, im AleppoFöhren-Bestand zwischen Hotel Bellevue und dem Strand, 14 May 2012, H. Teppner (herb. Teppner); Veli Losinj, Kapelle Sveti Ivan, Asphaltstraße auf dem Höhenrücken, Straßenrand, 24 Mar 2008, I. Uhlemann (herb. Uhlemann); Straße zwischen Veli Losinj und Mali Losinj, Straßenrand, 12 Apr 2007, I. Uhlemann (B, herb. Uhlemann). Pag, Nordspitze der Insel, Tovarnele, Ortslage, zwischen alten Olivenbäumen, 14 Apr 2009, I. Uhlemann (herb. Uhlemann). Rab, südwestlich der Stadt, Straße nach Suha Punta, Straßenrand c. 2 km nördlich des Ortes, 14 Apr 2010, I. Uhlemann (B, herb. Uhlemann); Rab, westlich der Stadt, Kampor, Naturlehrpfad südlich des Ortes, Wegrand, 11 Apr 2010, I. Uhlemann (B, herb. Uhlemann). Dalmatia, Norddalmatien, Starigrad, Velika Paklenica, c. 2 km oberhalb des Parkeingangs, Wegrand, 15 Apr 2009, I. Uhlemann (herb. Uhlemann).
I would like to thank Dr W. Rottensteiner (Austria, Graz) for providing specimens of his collections and Dr Jan Kirschner, Dr Jan Štěpánek, an anonymous reviewer and Nicholas Turland for their comments on an earlier version of this paper.