Taraxacum pomposum Štěpánek & Kirschner, 2013

Štepánek, Jan & Kirschner, Jan, 2013, A revision of mountain species of the genus Taraxacum F. H. Wigg. (Compositae) in Corsica, Candollea 68 (1), pp. 29-39 : 35-38

Taraxacum pomposum Štěpánek & Kirschner , spec. nova

( Fig. 2 , 3 , 4 ).

Typus: CORSE: “ Punta della Capella, au Sud-Est du Col de Verde . Replats herbeux des rochers à l’ubac. Silice”, 2000-2044 m, 30.VII.1910, J. Briquet, A. Saint-Yves & Fr. Cavillier s.n. (holo-: G-BU [ G00000836 ], n° det. 23269).

Plantae esectione Fontanorum, mediocriter altae rosulis pinguis cum 1-3 scapis et 4-8 foliis. Folia suberecta, longa, plerumque 9-18 cm longa et 2.5-3 cm lata, verisim. laete viridia, immaculata, glabra - persparse araneosa, lamina ambitu anguste oblanceolata, pinnatisecta - runcinate pinnatisecta, interdum pinnatipartita, lobo terminali fere subdominanti, 2-4 cm longo, 2-3 cm lato, ambitu triangulari - anguste triangulari, subinde subsagittato, acutissimo, margine distali aliquado integerrimo subsigmoideo sed saepius incisura profunda denteque valido acuto patento - prono nonnumquam utrimque ac vulgo dens in uno latere et incisura ultra (dextra - sinistra asymmetrice) praedito, lobulis basalibus patentissimis vel subdivaricatis, margine proximali ± recto vel subsigmoideo integerrimo, lobis lateralibus remotis subparvis, fere oppositis, numero 3-4 utrimque, deorsum in lobulos usque dentes longos decrescentibus, iismaioribus (i.e. duo pariasuperiora) triangularibus - late triangularibus, saepissime patentissimis, plerumque e basi lata in partem terminalem late lingulatam usque anguste lanceolatam ± subite coartatis, acutissimis, margine distali sigmoideo vel subconcavo, integerrimo vel ad basin dentibus paucis angustis acutissimisque praedito, margine proximali ± recto vel parum profunde undulato, subintegerrimo, involuto, interlobiis significantibus, 1-2 cm longis, mediocriter latis (4-5 mm), integerrimis vel argute sparseque longe dentatis, nervo mediano vix pallido. Petiolus anguste vel mediocriter alatus, ± longus, laete usque obscure roseus. Scapi ad 20 cm longi, foliis aliquanto longiores, persparse araneosi, densius sub calanthodio ad basin sne dubio rubro-violacei. Calathodia mediocriter magna, 2.5-3 cm i diametro, plana usque concava (?), verisimiliter pallide lutea. Involucrum Taraxacum scaturiginosum imitans, ad basin subrotundatum, ca. 8 mm in diametro, bracteis exterioribus ± adpressis - laxe adpressis, aliquando irregulariter patentibus, numerosis (18-21), imbricatis, anguste lanceolatis, plerumque 6-8 mm longis (in dimidiam partem bracteorum interiorum attollientibus), 2.3-3 mm latis, saepissime in tertia - quarta parte inferiore latissimis, obscure viridibus in limbum insignem pallidum (albidum - sordide album) submembranaceum 0.15-0.3 mm latum vergentibus. Ligulae ± breves, eae marginales subplanae, extus stria pallida cinerea (?) ornatae denticulis apicalibus griseo-atris vel paulum violascentibus, eae centrales angustioresque breviores, veris. canaliculatae denticulis fusco-cinereis usque olivaceis. Stigmata mediocriter longae, obscurae (virescente griseae extus atro-pilosae). Antherae polline carentes. Achenia(solum submatura ad manum sunt) pallide fulvostraminea, 4.0- 4.2 mm longa (pyr. incl.) corpore in quarta parte superiore spinuloso spinulis latis subacutis atque squamuloso deorsum sparse tuberculato - sublaevi, in pyramidem conicam 0.7-0.8 mm longam gradatim abeunti, rostro ca. 9 mm longo, pappo ca. 6.5 mm longo in herbario fuscescente sordide albido. Species agamosperma.

Description. – Plants medium-sized, each rosette of 4-8 leaves and 1-3 scapes, to 20 cm tall. Leaves ± suberect, usually 9-18 cm long, 2.5-3 cm wide, narrowly oblanceolate in outline, runcinate, runcinate-pinnatifid or runcinate-pinnatisect. Terminal lobe dominant, 2-4 cm long, 2-3 cm wide, triangular to narrowly triangular in outline, acute, distal margin slightly sigmoid, entire or more often with a distinct incision forming a big patent tooth on each side asymmetrically, basal lobules patent to recurved, proximal margin ± straight to sigmoid, entire. Lateral lobes not large, usually opposite, 3-4 pairs, getting smaller and substituted by lobules or long teeth near leaf base, upper 1-2 lobe pairs ± triangular to broadly so, usually patent, with broad base and subabruptly narrowed into a broadly lingulate to broadly linear acute distal part, distal margin sigmoid or ± concave, entire or with a few thin acute teeth, proximal margin ± straight, ± entire; margins of the incision between terminal lobe and the first lateral lobes raised upwards; interlobes distinct, 1-2 cm long, 4-5 mm wide, entire or sparsely dentate with long teeth; midrib pale; petiole narrowly to medium broadly winged, relatively long, light to deep pink. Scapes overtopping leaves, very sparsely aranose (sometimes more densely just below capitulum), probably purplish at base. Capitulum not big, 2.5-3 cm in diam., probably ± flat, (pale?) yellow. Involucre broadly rounded at base. Outer bracts ± appressed to loosely appressed, rarely to ± erect, numerous (18-21), imbricate, reaching 1/2 of the inner bracts, narrowly lanceolate, less often to lanceolate, usually 6-8 mm long, 2.3-3 mm wide, distally gradually narrowing into a long apex, ± evenly dark green, with a distinct pale or whitish to dirty white border 0.15-0.3 mm wide. Outer ligules relatively short, ± flat, striped light greyish beneath, apical teeth greyish black, central ligules narrower and shorter, apical teeth brownish to olivaceous. Stigmas dark, ± greenish grey, with black stigmatic hairs. Pollen absent. Achenes (not perfectly ripe available), light straw-brown, 4-4.2 mm long, achene body spinulose and squamulose in the upper 1/4, tuberculate to smooth below, ± subgradually narrowing into conical cone 0.7-0.8 mm long; beak at least 9 mm long; pappus dirty white, ca. 6.5 mm long. Agamosperm.

A very distinct species characterized by robust growth, small capitula, anthers without pollen, very dark stigmas and numerous narrow erect outer involucral bracts. It is probably the rarest of the subalpine Corsican endemics.

Distribution. – Endemic to Corsica.

Other specimen studied. – CORSE: Monte Padro , rochers, silice, 2300 m, 4.VII.1908, J. Briquet ( G-BU [ G00000837 ], n° det. 23280).

Figures

Fig. 2. – Taraxacum pomposum Štepánek & Kirschner. [Scale bar = 5 cm]. [Briquet & al. s.n., G-BU] [Drawing by J. Štepánek]

Fig. 3. – Holotype of Taraxacum pomposum Štepánek & Kirschner. [Briquet & al. s.n., G-BU]

Fig. 4. – Detail of flower head of Taraxacum pomposum Štepánek & Kirschner. [Briquet & al. s.n., G-BU]