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Phytotaxa 286 (3): 207–210 ISSN 1179-3155 (print edition)
http://www.mapress.com/j/pt/ Correspondence PHYTOTAXA
Copyright © 2016 Magnolia Press ISSN 1179-3163 (online edition)

http://dx.doi.org/10.11646/phytotaxa.286.3.10
A revision of Helichrysum panormitanum s.l. (Asteraceae) in the Italian and

Maltese floras

DUILIO IAMONICO , RICCARDO GUARINO , VINCENZO ILARDI & SANDRO PIGNATTI 4
2
3
1*
1 Department PDTA, University of Rome Sapienza, 00196 Rome, Italy; e-mail: d.iamonico@yahoo.it
2 Department STEBICEF - Botanical Unit, University of Palermo, 90123 Palermo, Italy.
3 Department STEMBIO, University of Palermo, 90123 Palermo, Italy.
4 Botanical Garden of Rome, Department of Environmental Biology, University of Rome Sapienza, 00196 Rome, Italy
*author for correspondence

As part of the ongoing researches on Asteraceae for the new edition of the Italian Flora, a revision of Helichrysum panor-
mitanum s.l. is presented here. On the basis of previously published morphological and chemical data, as well as our mor-
phological and chorological observations, we hereby propose to recognize six subspecies under H. panormitanum: subsp.
panormitanum, subsp. stramineum, subsp. brulloi subsp. nov., subsp. messeriae, subsp. latifolium, and subsp. melitense
comb. nov. All these taxa are endemic to Sicily and Egadi Islands (Italy), except H. panormitanum subsp. melitense which is
endemic to Gozo island (Maltese archipelago). A diagnostic key for the six accepted subspecies is provided.
Key words: Compositae, Egadi, Gozo, new combination, new subspecies, Sicily.

Helichrysum Miller (1754: without page, as “Elichrysum”) is one of the largest genera in Asteraceae, including 500−600
species distributed in Africa, Madagascar, the Mediterranean basin, Macaronesia, Western and Central Asia, and India (see
e.g., Hilliard 1983, Bayer et al. 2007, Galbany-Casals et al. 2009). This genus is considered difficult from the taxonomical
point of view, and recent studies (e.g., Bayer et al. 2000, Galbany-Casals et al. 2004) showed that it is polyphiletic. Galbany-
Casals et al. (2009) highlighted that its Mediterranean and Asiatic members form a monophyletic group, which expanded
and diversified particularly in the Mediterranean basin. As part of the preparation of the new edition of the Flora of Italy (the
previous flora was published by Pignatti 1982), some notes on the genus Helichrysum for the Italian peninsula are presented,
including the description of a new subspecies and a proposal for a new combination.
The circumscription of Helichrysum in Italy changed over the time. Pignatti (1982: 41−43), in the 1 edition of Flora of
st
Italy, treated 6 species (and 5 varieties), while the recent Checklist of the Italian Vascular Flora (Conti et al. 2005: 103−104)
listed 11 species (with 4 subspecies), and Greuter (2008: 234−239) accepted 8 species (with 5 subspecies) from Italy. The
new edition of the Flora of Italy [Pignatti (ed.), in prep.] will accept 14 species (with 5 subspecies), of which 9 are endemics
of the country (see also Peruzzi et al. 2015).
According to Aghababyan et al. (2007), Helichrysum panormitanum Tineo ex Gussone (1844: 467) is the correct name
for the Sicilian populations which were previously referred to under the illegitimate name H. rupestre Candolle (1838: 182).
Candolle (l.c.) cited H. pendulum (Presl 1822: 97) Presl (1826: XXIX) in synonymy, thus making his H. rupestre illegitimate
under Art. 52.2 of ICN (McNeill et al. 2012) (see also Aghababyan et al. 2007: 1286). Helichrysum panormitanum is an
endemic species restricted to the north-western area of Sicily. It includes robust and almost odourless plants characterized
by linear and tomentose leaves, capitula about as long as wide, involucral bracts usually acute to acuminate, and flowers
pale-yellow to yellow-golden. The typical form (s. str.) occurs in the mountains surrounding the plain of Palermo, whereas
the populations isolated in the coastal cliffs and islands of W-Sicily exhibit some distinctive morphologic traits, particularly
in the density and size of the inflorescence, colour and size of capitula, shape and width of the leaves (Brullo & Brullo
2013), and ultrastructural and morphologic characters of cypselas (Salmeri et al. 2014). These traits are sometimes feeble
but very constant and distinctive. Recent cytochemical analyses demonstrated, as well, some interpopulational variability in
secondary metabolites, which may be the result of an epigenetic and metabolic differentiation triggered by adaptive radiation
to the severe environmental conditions of coastal cliffs and mountain ecosystems (Maggio et al. 2016).

Accepted by Alexander Sennikov: 21 Nov. 2016; published: 30 Nov. 2016 207