The group of Centaurea (sect. Acrolophus) cineraria (Compositae) in Sicily includes four currently accepted species plus four taxa that have been considered, with some doubt, as subspecies of one of them (C. panormitana). In total, discounting recombinations and replacement names, 11 names (seven specific, three varietal, one of a forma), all based on Sicilian material, were published by past authors for these eight taxa. Two of the names had their holotype indicated upon publication; two have been lectotypified previously; six (C. busambarensis var. obtusiloba, C. cineraria var. soluntina, C. cineraria var. umbrosa, C. todaroi, C. todaroi f. seguenzae and C. ucriae) are lectotypified here; and C. panormitana is neotypified. The whole group is extremely variable and the delimitation of most taxa is still uncertain. Pending further study, including the sampling of wild populations, no taxonomic reassessment is therefore attempted here, with one exception: the merger of C. panormitana subsp. ucriae with C. panormitana subsp. panormitana.
Version of record first published online on 7 March 2016 ahead of inclusion in April 2016 issue.
Introduction
The group of Centaurea (sect. Acrolophus) cineraria L. (Compositae) comprises perennial chasmophytes growing in discrete populations in S Italy and Sicily, with few outliers in N and C Italy and Tunisia (see map in Hilpold & al. 2011). The group, or parts of it, have been the object of studies by Lacaita (1915), Cela-Renzoni & Viegi (1982) and, more recently, Raimondo & Bancheva (2004), Raimondo & al. (2004), Palla & al. (2005), Bancheva & al. (2006) and Hilpold & al. (2011). In Sicily, it comprises four currently accepted species: C. busambarensis Guss., C. erycina Raimondo & Bancheva, C. panormitana Lojac. and C. saccensis Raimondo & al. (Greuter 2008). Under C. panormitana, Greuter (2008) tentatively accepted four subspecies of uncertain value: C. panormitana subsp. seguenzae (Lacaita) Greuter, subsp. todaroi (Lacaita) Greuter, subsp. ucriae (Lacaita) Greuter and subsp. umbrosa (Fiori) Greuter. By general editorial policy of Med-Checklist (Greuter 2008) in such cases, C. panormitana subsp. panormitana is not given formal recognition; besides, owing to the fact that no original material of C. panormitana has so far been traced (Aghababyan & al. 2008), it is uncertain to which of the described subspecies, if to any, the type of C. panormitana belongs.
The group is polymorphic in several characters, which explains the high number of taxa described in it. However, intra-populational variation is considerable, even at the classical localities of the described taxa. It is, therefore, difficult to draw clear-cut limits between these taxa. Their taxonomic position, mutual relationship, perhaps even their recognition as distinct units need to be reconsidered and, with one exception, are not being commented on here. Studies of natural populations, their structure and variability are under way. In order to yield conclusive results, these studies will depend on clarity with regard to the correct application of the names that have been published so far, particularly those dating from the 19th and early 20th centuries, proposed by Gussone, Lojacono-Pojero and Lacaita, for many of which no types had been designated so far; the exceptions being Centaurea busambarensis, typified by Cela Renzoni & Viegi (1982), and C. busambarensis var. prostrata Lojac., typified by Aghabayan & al. (2008). For convenience, holotypified and previously lectotypified names are included in the following enumeration, which is placed within the frame of the initiative “Italian Loci Classici Census” (Domina & al. 2012; Peruzzi & al. 2015), aimed at locating the original material of vascular plants described from Italy.
Material and methods
Original material for the names of taxa of the Centaurea cineraria group described from Sicily was looked for in all relevant European herbaria, including B, BM, FI, G, K, NAP, PAL, PR, RO, W and WU (Herbarium acronyms according to Thiers [continuously updated]). A preliminary screening of the material was possible thanks to digital type images provided at JSTOR Global Plants ( http://plants.jstor.org) and other online sources of such images.
Original material of the names of taxa described by Lacaita is found essentially at the Natural History Museum, London (BM), where Lacaita's herbarium is kept. Gussone's material is to be looked for primarily in his Sicilian herbarium in Naples (NAP), where it is kept as a separate collection. That of Lojacono is kept in the Herbarium Mediterraneum, Palermo (PAL).
Results and Discussion
In total, discounting recombinations and replacement names, 11 names (seven specific, three varietal, one of a forma) based on material from Sicily are taken into account. For seven of them, the type is designated here: six names (Centaurea busambarensis var. obtusiloba Guss., C. cineraria var. soluntina Lojac., C. umbrosa Lacaita, C. todaroi Lacaita, C. todaroi f. seguenzae Lacaita and C. ucriae Lacaita) are lectotypified; C. panormitana is neotypified.
The prevailing uncertainty over the appropriate delimitation of the taxa of the group is borne out by the fact that even the type specimens of some of their names bear conflicting identifications.
Looking at the types here designated, it is possible to draw with confidence at least one taxonomic conclusion: Centaurea panormitana is the same as the taxon up to now generally known as C. panormitana subsp. ucriae; the latter name, therefore, falls into the synonymy of C. panormitana subsp. panormitana. We also confirm the synonymy of C. cineraria var. soluntina with C. panormitana subsp. todaroi, which had been established previously on the basis of the respective descriptions and indications of provenance.
In the following enumeration, names currently considered to be correct appear in bold italics.
Centaurea busambarensis Guss., Fl. Sicul. Syn. 2: 873. 1844–1845 ≡ Centaurea cineraria var. busambarensis (Guss.) Sommier in Nuovo Giorn. Bot. Ital., ser. 2, 1(2): 87. 1894 ≡ Acosta busambarensis (Guss.) Holub in Preslia 46: 226. 1974 ≡ Centaurea cineraria subsp. busambarensis (Guss.) Dostál in Bot. J. Linn. Soc. 71: 196. 1976. Ind. Loc.: “In saxosis calcareis montosis; Monti di Caltauturo; Busambra (Gasp.)”.
Lectotype (Cela Renzoni & Viegi 1983: 133): “Italy. Busambra, April 1824” [manu Gussone] (NAP!).
Centaurea busambarensis var. obtusiloba Guss., Fl. Sicul. Syn. 2: 873. 1844–1845 [= Centaurea busambarensis Guss.].
Ind. Loc.: “Dirupi sopra Isnello Guss. Heldr! (L. classic!) Vallata Reale (subtypica sub Centaurea Parlatori var. tomentosa Ross, in Herb. Pan.!)”.
Lectotype (designated here): “Centaurea Cineraria L., in rupibus calcareis a Isnello. Giugno 1840, Heldreich [manu Heldreich] / Busambarensis foliorum laciniis latis, Junio, Julio [manu Gussone]” (NAP!).
Centaurea busambarensis var. prostrata Lojac., Fl. Sicul. 2(1): 135. 1903 [= Centaurea busambarensis Guss.].
Ind. Loc.: “Centaurea prostrata Huet exsic. Sic. ann. 1855, C. cinereo-humilis Guss. exs. C. Pariatoris Herb. Pan. (p. partem) / Passo della Botte Ross! (sub C. Parlatoris) Scalonazzo Lojac!, Carbonara Lojac! dirupi d'Isnello ed in tutte le rupi elevatissime che sovrastano Montaspro”.
Lectotype (Aghababyan & al. 2008): “Giugno, Centaurea parlatoris b. tomentosa Guss. Isnello dirupi [manu Tineo] / non è la C. parlatoris [manu Lojacono, on sheet]” (PAL10796!).
Centaurea cineraria var. soluntina Lojac. in Naturalista Sicil. 3: 210. 1884 ≡ Centaurea soluntina (Lojac.) Tin. ex Lojac., Fl. Sicul. 2(1): 135. 1903 [= Centaurea panormitana subsp. todaroi (Lacaita) Greuter].
Ind. Loc.: “In rupibus calcareis maritimis boream spectantibus Catalfano Tin! Porc. M. L.” — No original material traced by Aghababyan & al. (2008).
Lectotype (designated here): “Addi 8 Giugno 1849 [manu Porcari], Centaurea cinerea b. glabrata Tin [manu Todaro], Raccolta da Donrei[?] a Catalfano [manu Porcari]”, ex herb. Porcari (PAL!).
Centaurea erycina Raimondo & Bancheva in Bocconea 17: 299. 2004.
Ind. Loc.: “San Giuliano Mt. Venus Castle (Erice village)”.
Holotype: Italy, Sicily, San Giuliano Mt, Venus' castle (Erice village), 38°02′N, 12°35′E, 600 m a.s.l., carbonate rocks, 31 May 1990, Raimondo & al. 0485 (PAL69493!; isotypes: B!, CAT!, G!, PAL!, RNG!, SEV!, SOM!).
Centaurea panormitana Lojac., Fl. Sicul. 2(1): 137. 1903. Ind. Loc.: “a S. Martino via della Portella di S. Anna”. Neotype (designated here): Centaurea panormitana Lojac. subsp. panormitana, Italy, Sicily, Monreale, Punta Mastrangelo, 38°03′52″N, 13°14′37″E, 850 m a.s.l., carbonate cliff facing the sea, 3 Aug 2015, Domina (PAL102714!; isoneotypes: B!, BM!, FI!, PAL-Gr!, RO!).
Note — No original material was traced by either Aghababyan & al. (2008) or ourselves. The first author searched for the plant at the locus classicus several times, alas in vain. The neotype here designated was collected in a close-by locality with identical soil, climatic conditions, altitude and exposure.
Centaurea succensis Raimondo & al. in Bocconea 17: 293. 2004.
Ind. Loc.: “Tardara Gorge (near Sciacca Town)”. Holotype: Italy, Sicily, Tardara Gorge (near Sciacca town), 37°37′01″N, 13°03′17″E, 100 m a.s.l., crevices of limestone rocks, 2 Jun 1990, Raimondo & al. 0861 (PAL69494!; isotypes: B!, CAT!, G!, PAL!, RNG!, SEV!, SOM!).
Centaurea todaroi Lacaita in Nuovo Giorn. Bot. Ital. 22: 245. 1915 ≡ Centaurea ucriae subsp. todaroi (Lacaita) Cela Renz. & Viegi in Atti Soc. Toscana Sci. Nat., Mem. Ser. B 89: 130. 1983 ≡ Centaurea panormitana subsp. todaroi (Lacaita) Greuter, Med-Checklist 2: 126. 2008. Ind. Loc.: “Monte Catalfano presso Bagheria”. Lectotype (designated here): “Centaurea cinerea Lam. dict. enc. 1, p. 669, In rupibus calcareis — Palermo a Catalfano, Aprili, n. 820, Legit Todaro” (BM001043179!; isolectotypes: FI!, PAL10711!).
Centaurea todaroi f. seguenzae Lacaita in Nuovo Giorn. Bot. Ital., ser. 2, 22: 246. 1915 ≡ Centaurea todaroi subsp. seguenzae (Lacaita) Giardina & Raimondo in Bocconea 20: 10, 393. 2007 ≡ Centaurea panormitana subsp. seguenzae (Lacaita) Greuter, Med-Checklist 2: 126. 2008.
Ind. Loc.: “Nasce al Capo Tindaro, dove la scoprì Seguenza e dove l'ho raccolta copiosamente”.
Lectotype (designated here): “Centaurea Todari, var. Seguanzae Lacaita, in N. G. Bot. It. April 1915, sea cliffs of Capo Tindaro, north coast of Sicily, legi 9 Jun 1907, CCL. [Manu Lacaita]” (BM1043166!).
Centaurea ucriae Lacaita in Nuovo Giorn. Bot. Ital. 22: 244. 1915 ≡ Centaurea panormitana subsp. ucriae (Lacaita) Greuter, Med-Checklist 2: 126. 2008 [= Centaurea panormitana Lojac. subsp. panormitana].
Ind. Loc.: “Nasce non molto copiosa al M. Pellegrino di Palermo dove l'ho raccolta sopra la Favorita. È indicata di Alcamo, Trapani, M. Cofani, Sciacca e delle isole di Favignana, Levanzo e Marettimo.”
Lectotype (designated here): “Herb. Lacaita, Centaurea ucria, Palermo al Monte Pellegrino, ad rupes calcarea, in loco dicto “Valle del Porco”, 3 Jun [19]07 / Centaurea ucria mihi, CCL 9566” (BM1043192!).
Note — Lacaita (1915) described two species from Monte Pellegrino, near Palermo, with different ecology: Centaurea umbrosa, exposed to sea moisture on the slope facing Mondello, and C. ucriae, more thermophilous, on the slope facing inland, toward the Favorita park. The specimen here selected was used for the preparation of plate iv in Lacaita (1915).
Centaurea umbrosa Lacaita in Nuovo Giorn. Bot. Ital., ser. 2, 22: 246. 1915 [non Reut. 1856] ≡ Centaurea cineraria var. umbrosa Fiori, Nuova Fl. Ital. 2: 726. 1927 ≡ Centaurea cineraria subsp. umbrosa (Fiori) Pignatti in Giorn. Bot. Ital. 113: 366. 1980 ≡ Centaurea ucriae subsp. umbrosa (Fiori) Cela Renz. & Viegi in Atti Soc. Toscana Sci. Nat, Mem. Ser. B 89: 128. 1983 = Centaurea panormitana subsp. umbrosa (Fiori) Greuter, MedChecklist 2: 126. 2008 ≡ Centaurea tyrrhena C. Brullo & al. in Peccenini & Domina, Loc. Class. Fl. Italia: 36. 2011.
Ind. Loc.: “L'ho raccolta ad oriente della città a Chirandà e ad occidente sulle rupi di Monte Gallo che cadono dalla Portella di Spartivento al lido del mare verso Sferracavallo. Cfr. Lojac. Pl. Sic. Rar., n. 592.”
Lectotype (designated here): Centaurea umbrosa (mihi), = C. cinerea Guss et Lojacono, (an et Lam?), (Palermo) Chiarandà ad rapes umbrosa, 16 Nov [19]05, [Lacaita] 25 (BM1043173!).
Note — The lectotype specimen is from Chiarandà, a locality situated on Mt Grifone at a distance of c. 10 km from Mt Gallo and the close-by Mt Pellegrino, where also Centaurea panormitana subsp. panormitana grows. We have thought it preferable to select material that does not originate from a locality so close to a population of a different, related taxon.
Acknowledgements
We thank Dr Roberta Vallariello (NAP) and Ranee Prakash (BM) for their valuable aid in tracing the original material in the Gussone and Lacaita Herbaria, respectively, and an anonymous reviewer for comments on an earlier draft of this paper.
