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Notes:―Within H. panormitanum, Gussone recognized two varieties: ”a-angustifolium“ (locus classicus is ”Scale
Maseddu“) (corresponding to H. panormitanum s.str.), and ”b-latifolium“ (locus classicus is Cape Zafferano, i.e. the place
where the specimen chosen by Galbany-Casals et al. (cit.) for the lectotypification of H. panormitanum var. latifolium was
collected). The latter variety, for its distinctive morphological and biochemical traits, was then promoted to the rank of
subspecies by Maggio et al. (2016).

Helichrysum panormitanum subsp. melitense (Pignatti) Iamonico & Pignatti, comb. nov. ≡ Helichrysum rupestre var.
melitense Pignatti (1979: 363) ≡ Helichrysum melitense (Pignatti) Brullo, Lanfranco, Pavone & Ronsisvalle (1988:
45).
Type:―MALTA. Insula Gaulo [Gozo], in rupibus maritimis, Cala Dwejra, 30 March 1874, Duthie s.n. (FI!, holotype, image available at
http://parlatore.msn.unifi.it/types/search.php).

Distribution:―Endemic to the Island of Gozo (Maltese Archipelago).
Notes:―This is the most differentiated among the taxa belonging to the H. panormitanum group. It was described by
Pignatti (1979: 363) as H. rupestre var. melitense, and subsequently treated at species rank by some authors (see Greuter 2006+,
2008), as H. melitense (Pignatti) Brullo, Lanfranco, Pavone & Ronsisvalle (1988: 45). In the light of the already mentioned
(see the Introduction for details) recent, accurate studies about the interpopulational variability of H. panormitanum, it can
be presumed that the differentiation of this species is the result of a local adaptive radiation triggered by Plio-Pleistocenic
environmental changes, as it happened with many other elements of the Mesogean flora (Guarino et al. 2006). All the W-
Sicilian populations exhibit close affinities and their differentiation is probably a very recent result of Pleistocenic events, but
also the populations of Malta and Pantelleria are clearly related to the same group, even if their isolation could be older. In
order to emphasize the common biogeographic history, it is here preferred to treat the Maltese population as a subspecies of
H. panormitanum. As for Pantelleria, where H. errerae Tineo occurs, the problem remains open because the differences from
H. panormitanum are even more remarkable than in the case of the Maltese population. This is probably due to a secondary
adaptation to volcanic rocks, whereas the Maltese population remained faithful to limestone cliffs, i.e. the typical, pristine
habitat of H. panormitanum.

A diagnostic key for subspecies of Helichrysum panormitanum

1. Capitula 5.0−6.0(−7.0) mm in diameter, arranged in dense or lax corymbs .................................................................................... 2
– Capitula 4.0−4.5 mm in diameter, always arranged in dense corymbs ............................................................................................ 5
2. Leaves flat, lanceolate, 30−40 × 2−3 mm ........................................................................................................................................ 3
– Leaves linear to linear-lanceolate, (20−)30−60(−80) × 1−2 mm ..................................................................................................... 4
3. Stems 30−50 cm, capitula golden yellow, 5 mm in diameter ..................................................... H. panormitanum subsp. melitense
– Stems (40−)50−70(−80) cm, capitula pale-yellow, 5−6 mm in diameter .................................. H. panormitanum subsp. latifolium
4. All leaves revolute, capitula arranged in lax corymbs, involucral bracts golden-yellow ... H. panormitanum subsp. panormitanum
– Lower leaves flat or slightly revolute, capitula arranged in dense corymbs, involucral bracts pale-yellow .......................................
......................................................................................................................................................... H. panormitanum subsp. brulloi
5. Leaves flat or slightly revolute, 2.0−4.0 mm wide, inner involucral bracts 5.0−6.0 mm long ...........................................................
................................................................................................................................................. H. panormitanum subsp. stramineum
– Leaves revolute, 1.0−2.0 mm wide, inner involucral bracts 3.0−4.0 mm long ......................... H. panormitanum subsp. messeriae

References

Aghababyan, M., Greuter, W., Mazzola, P. & Raimondo, F.M. (2007) Typification of Sicilian Helichrysum (Asteraceae) revisited. Taxon
56: 1285–1288.
https://doi.org/10.2307/25065922
Arcangeli, G. (1894) Compendio della flora italiana, ed. 2. E.Loescher, Torino e Roma, 836 pp.
Bayer, R.J., Puttock, C.F. & Kelchner, S.A. (2000) Phylogeny of South African Gnaphalieae (Asteraceae) based on two noncoding
chloroplast sequences. American Journal of Botany 87: 259–272.
https://doi.org/10.2307/2656914
Bayer, R.J., Breitwieser, I., Ward, J. & Puttock, C.F. (2007) Tribe Gnaphalieae (Cass.) Lecoq & Juillet. In: Kadereit, J.W. & Jeffrey, C.
(Eds.) The families and genera of vascular plants, vol. 8. Springer, Berlin, pp. 246–284.
Brullo, S., Lanfranco, E., Pavone, P. & Ronsisvalle, G. (1988) Taxonomical notes on the endemic flora of Malta. Nuovo Giornale Botanico

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