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

XIV OPTIMA Meeting, Palermo (Italy), 9-15 September 2013
A new species of Euphorbia (Euphorbiaceae) from Greece and its phylogenetic
placement within E. sect. Patellares
CONSTANTINIDIS T. 1 , KALPOUTZAKIS E. 2 , KOUVELIS V. 3
1 Department of Ecology & Systematics, Faculty of Biology, National & Kapodistrian University of Athens, Athens, Greece.
E-mail: constgr@biol.upa.gr
2 Division of Pharmacognosy – Chemistry of Natural Products, School of Pharmacy, University of Athens, Athens, Greece.
E-mail: elkalp@pharm.uoa.gr
3 Department of Genetics & Biotechnology, Faculty of Biology, National & Kapodistrian University of Athens, Athens,
Greece. E-mail: kouvelis@biol.uoa.gr
The large genus Euphorbia L. comprises approximately 54 species in Greece, including members of
subgenus Chamaesyce Raf. that mostly represent allochthonous species. Some recent collections of
Euphorbia from southern Greece represent an undescribed species within E. sect. Patellares. The new
species is a perennial plant scarcely woody at base, with entire margins of cauline leaves, connate
raylet leaves subtending cyathia, and apparently smooth seeds. Its stems are mostly biennial with
cauline leaves strongly dimorphic: those of first-year are obovate to obovate-lanceolate in outline while
those of second year orbicular to reniform. The inflorescence is short and lax, developed on 1-4 rays.
Preliminary results of a Bayesian phylogenetic reconstruction within Euphorbia sect. Patellares
based on both ribosomal and chloroplast regions indicate that the affinities of the new species should
not be searched within the polymorphic E. amygdaloides group represented in Greece by E. amygdaloides
L. and E. heldreichii Orph. ex Boiss. Instead, the new species is related to a group of mostly
Asiatic taxa (albeit with low posterior probabilities at present) including E. kotschyana Fenzl, E.
davisii M.S. Khan and E. oblongifolia (K. Koch) K. Koch. The molecular results are in accordance
with morphological evidence. Euphorbia davisii from the Taurus Mountains (Turkey) appears to be the
closest relative of the new species. From E. davisii the Greek species differs in a number of morphological
characters of stem, leaves and inflorescence and is separated by a distance of 800-950 km.
The chromosome number of the new species is 2n = 20. The same number is common in other members
of Euphorbia sect. Patellares.
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