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

XIV OPTIMA Meeting, Palermo (Italy), 9-15 September 2013
Towards a Critical Flora of Italy: Assessing the Lycopodiophyta
TROIA A., GREUTER W.
1 Dipto. di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo, Palermo, Italy.
E-mail: angelo.troia@unipa.it
2 Herbarium Mediterraneum Panormitanum, Università degli Studi di Palermo, Palermo, Italy.
In the framework of the project for a new Critical Flora of Italy, promoted by the Società Botanica
Italiana and supported by the Fondazione per la Flora Italiana together with the International
Foundation pro Herbario Mediterraneo, preliminary results relating to the lycophytes
(Lycopodiophyta), the most primitive extant group of vascular plants, are presented.
It is now generally agreed that an early phylogenetic dichotomy occurred in the early-mid Devonian
(ca. 400 million years ago), separating a clade that includes the modern lycophytes (less than 1% of
extant vascular plants) from a clade that contains all other living vascular plant lineages, the so called
“euphyllophytes” (Pryer & al., Amer. J. Bot. 91: 1582–1598. 2004). The extant lycophytes all possess
“microphylls” and comprise three main lineages: homosporous Lycopodiaceae (clubmosses), and heterosporous
Isoetaceae (quillworts) and Selaginellaceae (spikemosses).
Ferns and lycophytes, spore-bearing and lacking seeds, are traditionally known as pteridophytes or
“ferns and fern allies”. This is a paraphyletic assemblage that for the purpose of a natural classification
is better abandoned. It is preferable, in a taxonomic context, to use the name Pteridophyta for the ferns
alone and refer to the basal clade as Lycopodiophyta.
After a critical re-examination of previous literature and concomitant herbarium studies, we present
the following inventory of the Italian representatives of the three Lycopodiophyta families:
Lycopodiaceae. – Three genera with 8 species: Huperzia Bernh. (1 species), Lycopodiella Holub (1
species), and Lycopodium L. (6 species). According to recent molecular studies (e.g. Wikström &
Kenrick, Molec. Phylogenet. Evol. 19: 177-186. 2001), the genus Diphasiastrum Holub (= Diphasium
C. Presl ex Rothm. p.p.), accepted in several recent works, is better treated at sectional level, as
Lycopodium sect. Complanata Victorin (3 species and their 3 hybrids). We accept as a member of the
Italian flora L. lagopus (Laest. ex Hartm.) Zinserl. ex Kusen. (= L. clavatum subsp. monostachyon
(Desv.) Selander), a controversial taxon re-evaluated and reported for Italy by Tribsch & Schönswetter
(Verh. Zool.-Bot. Ges. Österreich 136: 235-248. 1999).
Isoetaceae. – One genus with 10 taxa: Isoetes L. The circumscription, and identification of Isoetes
species remain difficult because, due to the extreme morphological simplicity of the plants combined
with phenotypic plasticity, the number of stable and useful diagnostic characters is very limited. Our
work (in press) included new type designations and some nomenclatural novelties.
Selaginellaceae. – One genus with 3 species: Selaginella P. Beauv., with the arctic-alpine S. selaginoides
(L.) P. Beauv., S. helvetica (L.) Spring and S. denticulata (L.) Spring. The genus should probably
be split into subgenera and/or sections, but this is not appropriate without a previous critical assessment
on a world scale of its ca. 750 species.
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