Scientists map genetic history of obscure plant genus spanning Madagascar to Caribbean
Researchers have completed the first comprehensive classification of Paramollugo, a widespread but little-known plant genus, identifying 11 species and clarifying their evolutionary relationships across three continents. The work matters for biodiversity conservation efforts and may inform research into the plant's potential agricultural or pharmaceutical properties.
Originaltitel: Phylogeny and systematics of Paramollugo (Molluginaceae)
<p>The genus <em>Paramollugo</em> Thulin (<em>Molluginaceae</em>) comprises herbs or small shrubs or subshrubs mainly distributed in the Madagascar region, but one species also widespread in the tropics and subtropics of the Old World, two restricted to the Caribbean and one to New Caledonia. In the revision presented here 11 species are recognized: <em>P.</em> <em>decandra</em> (Scott Elliot) Thulin, <em>P. caespitosa</em> (Scott Elliot) Thulin comb. nov., <em>P. compressa</em> Thulin sp. nov., <em>P. simulans</em> Sukhor. and <em>P. elliotii</em> Sukhor. endemic to Madagascar, <em>P. nudicaulis</em> (Lam.) Thulin in Madagascar and also widespread on neighbouring islands and in tropical and subtropical parts of Africa and Asia, <em>P. angustifolia</em> (M.G. Gilbert & Thulin) Thulin in Madagascar and Somalia, <em>P. digyna</em> (Montrouz.) Sukhor. endemic to New Caledonia, <em>P. nesophila</em> Thulin et al. sp. nov. endemic to îles Éparses (Scattered Islands) in the Mozambique Channel, <em>P. spathulata</em> (Sw.) Sukhor. widespread in the Caribbean, and <em>P. cuneifolia</em> (Griseb.) Thulin endemic to Cuba. For each species descriptions and discussions are provided, as well as illustrations and distribution maps. New lectotypes are designated for <em>Mollugo caespitosa</em> Scott Elliot and <em>M. digyna</em> Montrouz. The phylogeny of the genus is reconstructed based on plastid trnK-matK and nuclear ITS sequences. Conflict between the datasets is seen as a result of the genus probably being a polyploid complex. Dating of the phylogeny resulted in two alternative topologies, both estimating the age of the stem clade to the Eocene, with a presumed origin in Africa, and mid-Miocene as the age of the crown clade, with a presumed origin in Madagascar and/or the Caribbean. The age of the crown clade is also the estimated date for a split between a Caribbean clade and the rest of the genus, long distance dispersal from Madagascar to the Greater Antilles being the most likely explanation.</p>