Abstracts, XIV OPTIMA Meeting, Palermo (Italy) , 9-15

XIV OPTIMA Meeting, Palermo (Italy), 9-15 September 2013
Polypodium macaronesicum reassessed
ROBBA L. 1 , RUMSEY F. J. 2 , SCHNEIDER H. 2 , CARINE M. A. 2
1 Dipartimento STEBICEF, Universita’ degli Studi Palermo, Palermo, Italy. E-mail: lavinia.robba@unipa.it
2 The Natural History Museum, London, U.K.
The Polypodium cambricum aggregate within the Macaronesian region and the relationships of these
plants to their mainland counterparts has long been controversial.
The P. cambricum aggregate distributed in Europe, North Africa and Western Asia, from
Macaronesia in the West (archipelagos of the Azores, Madeira and the Canaries) to the Caucasus in the
East, comprises taxa at three ploidy levels on the continent: the diploid P. australe Fée (= P. cambricum
L.), the tetraploid P. vulgare L. and the hexaploid P. interjectum Shivas.
The Polypodium commonly encountered in Macaronesia is diploid. Fée (1852) suggested that this
was distinct from the continental P. australe and formally recognised it as P. vulgare var. teneriffae Fée
ex Milde (Milde, 1867); Bobrov (1964) subsequently proposed the distinction at specific level as P.
macaronesicum A.E. Bobrov.
Nardi (1977) considered material from Macaronesia and the Mediterranean and recognised the
Macaronesian taxon as a subspecies of P. australe. Roberts (1980) argued that there were clear, unambiguous
and discontinuous characters to separate Macaronesian and continental taxa and that specific
rank was most appropriate.
Within Macaronesia, the distribution maps by Bobrov (1964) suggested that the Canaries and
Madeira exclusively support P. macaronesicum whereas in the Azores the presence of P. australe (= P.
cambricum) was ambiguously indicated. Vasconcellos (1968) subsequently described P. vulgare subsp.
azoricum from the Azores; Fernandes (1968) considered the Azorean taxon to be distiguishable from
the Canaries and Madeira one using rhizome characters and recognised the former at specific rank as
P. azoricum (Vasc.) R. Fernandes. However, Ward (1970) and Neuroth (1996) considered the characters
used by Fernandes (1968) to be unreliable, suggesting that frond shape and degree of toothing to
the rhizome scales were more useful. Nardi (1977) could identify no clear morphological distinction
between P. macaronesicum and P. azoricum and considered them all to be the same taxon (P. cambricum
subsp. azoricum (Vasc.) Nardi).
In view of the above sequence data from the chloroplast trnL-F region are used to test the delimitation
of putative species in Polypodium cambricum aggregate. In particular we investigate the distinctiveness
of the Macaronesian Polypodium macaronesicum, P. azoricum and the continental P. cambricum,
investigate molecular diversity patterns within Macaronesia and establish the identity of putative
P. macaronesicum material collected from an area in southern Spain.
The analysis supports the distinction of Macaronesian and continental plants with accessions from
Macaronesia resolved as monophyletic. All Macaronesian haplotypes were restricted to a single archipelago
and they were resolved into archipelago groupings in statistical parsimony analysis suggesting
limited dispersal between archipelagos.
Material from southern Spain referred to P. macaronesicum is shown to exhibit the Azorean haplotype,
consistent with its morphology.
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