Page 1 - Passalacqua_Peruzzi_Pellegrino2008

TAXON 57 (3) • August 2008: 893–906 Passalacqua & al. • Biosystematics of the Jacobaea maritima group

A biosystematic study of the Jacobaea maritima group (Asteraceae,
Senecioneae) in the Central Mediterranean area

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Nicodemo G. Passalacqua , Lorenzo Peruzzi & Giuseppe Pellegrino 3
1 The Natural History Museum of Calabria and Botanic Garden, University of Calabria, 87030, Arcavacata
di Rende (CS), Italy. nicodemo@unical.it (author for correspondence)
2 2 Department of Biology, Unit of general and systematic botany, University of Pisa, via Luca Ghini 5,
56126, Pisa, Italy
3 Department of Ecology, University of Calabria, 87030, Arcavacata di Rende (CS), Italy

The biosystematics of Jacobaea maritima (L.) Pelser & Meijden and four closely related taxa in the Central
Mediterranean area has been studied. Nine representative populations of five taxa (J. maritima subsp. maritima,
subsp. bicolor, subsp. gibbosa, J. ambigua subsp. ambigua and subsp. nebrodensis) were analysed. Molecular
LEU
analysis confirms close relationships among taxa (trn LEU and ITS II sequences are identical); ITS I and ISSR
analysis, on the other hand, shows some variability. Multivariate PCoA, based on 22 morphological variables,
shows a gradient connecting all populations; a rather clear grouping of taxa is obtained, however, when the
population from Levanzo is excluded. Finally, a new subspecies, J. maritima subsp. sicula, is proposed.

KEYWORDS: Asteraceae, Jacobaea, J. maritima group, molecular systematics, morphometry, phylogeny,
Senecio cineraria, speciation

Tundis & al. (2005) studied the variation of non-polar
INTRODUCTION chemical compounds in Italian taxa, and their results only
Senecio cineraria DC. ( ≡ Jacobaea maritima (L.) partially agree with the current taxonomic arrangement.
Pelser & Meijden) is a well known plant, widely grown The same applies to the variation pattern of pyrrolizidine
in European gardens. It forms a species complex with alkaloids (Tundis & al., 2007).
six other taxa, widespread in the Mediterranean area: The present study aims at verifying the current taxo-
Senecio gibbosus (Guss.) DC., S. bicolor (Willd.) Tod., nomic arrangement and at improving our understanding
S. ambiguus (Biv.) DC., S. ambiguus subsp. nebrodensis of the relationships between the taxa. To this purpose,
(Guss.) Peruzzi & N.G. Passal., S. gnaphalodes Sieber we performed molecular and morphometric analyses of
and S. taygeteus Boiss. & Heldr. The main diversity of nine populations of J. maritima group across the Central
the group lies in the Central Mediterranean (Chater, 1974; Mediterranean area. Questions addressed in this paper
Chater & Walters, 1976; Pignatti, 1982; Herborg, 1992). are: (1) To what degree are the different taxonomic units
These taxa have been variously recognised at subspe- distinct? (2) Is the distinction between J. maritima s.l. and
cific rank, within various species, within both Senecio and, J. ambigua s.l. consistent at species level? (3) What are the
most recently, Jacobaea. These treatments are summarised systematic relationships within this group?
in Table 1. Although we favour the recognition of these taxa
at subspecific rank within two species, for the purposes of
discussion we refer to these entities as J. ambigua, J. bi-
color, J. gibbosa, J. maritima, J. nebrodensis and J. tay- MATERIALS AND METHODS
getea. The J. maritima s.l. includes J. bicolor, J. gibbosa and Plant material. — The study was based on herbar-
J. maritima, whereas J. ambigua s.l. includes J. ambigua ium specimens from CAT, CLU, FI, NAP, PI and RO and
and J. nebrodensis. The studied taxa are stenoendemic living material (Appendix 1). Digital photos and/or speci-
(J. ambigua, J. gibbosa, J. nebrodensis) or show a wider men data information were obtained from B, BASSA,
distribution but with rather scattered stands (J. maritima, BM, BRNM, G, K and LIV.
J. bicolor). Preferential habitats are coastal cliffs (J. mar- Field investigations were conducted mainly in Tuscany
itima s.l.) or hilly-mountainous screes (J. ambigua s.l.). (C. Italy), Calabria (S. Italy), Sicily and the Eolean islands
Little is known about the breeding system in Jacobaea (Table 2) and included seven populations of J. maritima
(Kirk & al., 2005). Based on evidence from related genera s.l. (Table 2, pop. 1–7) and two of J. ambigua s.l. (8–9).
(Gibbs & al., 1975) we assume the J. maritima group to Twenty individuals of each population (a total of 180 indi-
be amphimictic. viduals) were used both for molecular and morphometric

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