Az Eszterházy Károly Tanárképző Főiskola Tudományos Közleményei. 2004. Sectio Biologiae. (Acta Academiae Paedagogicae Agriensis : Nova series ; Tom. 25)

Pócs, T.: New or little known epiphyllous liverworts, XI. Otolejeunea subana sp. nov. from Madagascar.

52 Pócs T. Discussion The new species differs well from both related taxa in the following characters: Smaller in size than both species (shoots of O. rabenorii are 1.6, of O. semperiana 1.8 mm wide, the stem of O. rabenorii is 100 pm and that of O. semperiana ca. 80 pm thick). The lobules of the new species are much longer, ovato-lanceolate in shape, attaining almost the half lobe length while those of the two related taxa are rounded ovate and short (1/4 - 1/3 o lobe length). Only O. subana has among the three species at least obsolete lobule teeth bordering an incision on the distal third of lobule margin. Only this species has elongated ellipsoid female bracteole with very short, rounded lobes. Only O. subana has a perianth with its rounded ears standing so closely to each other, that the sinus between them became obcordate. This feature is unique within the genus. In addition, the perianth of O. subana, together with the large ears, is longer than wide while in O. semperiana is wider than long. The perinth mouth in O. subana is without a beak while O. rabenorii has very long beak. Phytogeographycally interesting, that only New Guinea and Madagascar have three species together, being diversity centers of the genus. Then both large islands have an endemic subgenus, Madagascar has the representative of subgen. Otolejeunea, while New Guinea has that of Phoxolejeunea. Indomalesia has four species scattered on a much larger area while only one species is know from the Neotropis. Speculating on the evolutionary trends within the genus, I suppose that subgen. Otolejeunea with O. moniliata bears most of the ancestral characters, like the vitta and the well developed lobular teeth and hyaline papilla. The habitat preference in O. moniliata was not specialized yet, occurring on all substrates, while all other species are quite strictly epiphyllous. Then, after loosing the ocelli, the evolution took place in two directions. In subgen. Phoxolejeunea with O. streimannii the acute, long lobule tooth became reduced to a short, roundish cell, but still always present. At the same time evolved the perianth with acute lobes. In the other direction subgen. Allorgella has evolved, retaining the rounded auriculate perianth and at the same time the lobule structure was reduced at different levels. Only in O. subana and in O zanteni can still recognise the highly reduced lobule tooth, while in the second species the lobule margin starts to be inrolled and the whole lobule reduced. In O. rabenorii the lobule teeth disappear but the lobule margin is still visible. By all other species of the subgenus the lobule margin is fully incurved and teeth and papilla reduced together with the whole lobule. If we accept this evolution process, Madagascar and New Guinea retained the most ancient, less reduced types.