Phylogenetics and classification of the pantropical fern family Lindsaeaceae

Abstract

The classification and generic definition in the tropical-subtropical fern family Lindsaeaceae have been uncertain and have so far been based on morphological characters only. We have now studied the evolutionary history of the Lindsaeaceae by simultaneously optimizing 55 morphological characters, two plastid genes (rpoC1 and rps4) and three non-coding plastid intergenic spacers (trnL-F, rps4-trnS and trnH-psbA). Our data set included all genera associated with Lindsaeaceae, except Xyropteris, and c. 73% of the currently accepted species. The phylogenetic relationships of the lindsaeoid ferns with two enigmatic genera that have recently been included in the Lindsaeaceae, Cystodium and Lonchitis, remain ambiguous. Within the monophyletic lindsaeoids, we found six wellsupported and diagnostic clades that can be recognized as genera: Sphenomeris, Odontosoria, Osmolindsaea, Nesolindsaea, Tapeinidium and Lindsaea. Sphenomeris was shown to be monotypic; most taxa formerly placed in that genus belong to the Odontosoria clade. Ormoloma is embedded within Lindsaea and therefore does not merit recognition as a genus. Tapeinidium is sister to a clade with some species formerly placed in Lindsaea that are morphologically distinct from that genus and are transferred to Osmolindsaea and Nesolindsaea, proposed here as two new genera. We do not maintain the current subgeneric classification of Lindsaea itself, because neither of the two generally accepted subgenera (Lindsaea and Odontoloma) is monophyletic, and most of the sections also appear unnatural. Nesolindsaea shows an ancient biogeographical link between Sri Lanka and the Seychelles and many of the main clades within Lindsaea have geographically disjunct distributions.

Flora das cangas da Serra dos Carajás, Pará, Brasil: Lindsaeaceae

“…é uma família monofilética, com sete gêneros e cerca de 234 espécies (PPG I 2016), possui distribuição pantropical, com algumas espécies estendendo-se à regiões subtropicais na América do Sul, leste da Ásia e Nova Zelândia (Lehtonen et al 2010). São plantas terrícolas ou menos comumente rupícolas; caule curto a longo-reptante, geralmente protostélico, ocasionalmente solenostélico, com escamas ou tricomas; lâmina 1-3-pinada ou mais decomposta, quase sempre glabra; venação geralmente livre, eventualmente anastomosada; soros marginais ou submarginais, com indúsio extrorso (Smith et al 2006).…”

“…Gênero pantropical, monofilético (Lehtonen et al 2010), com cerca de 180 espécies (PPG I 2016). Das 30 espécies conhecidas no Brasil, 25 ocorrem na região norte do país (Prado et al 2015).…”

A new species of <I>Odontosoria</I> (<I>Lindsaeaceae</I>) from New Guinea

“…These species also share a short, typically uninerval, sori. Odontosoria chinensis and O. biflora were resolved as sister species pair in the cladistic analysis, but the phylogenetic relationships of O. quadripinnata and O. veitchii remain uncertain, due to the lack of molecular data (Lehtonen et al 2010). However, it is probable that all Odontosoria species with monolete spores are closely related.…”

“…Recent studies on Lindsaeaceae systematics (Lehtonen et al 2010) revealed two collections of a morphologically unusual Odontosoria from New Guinea. These specimens probably represent the 'quadripinnate form' of Sphenomeris retusa (Cav.)…”

“…However, the specimens in question differ from O. retusa not only by laminar dissection, but they also have uninerval sori and monolete spores in contrast to the continuous sori and trilete spores in O. retusa. This apparently undescribed taxa was not included in the family-level phylogenetic analysis (Lehtonen et al 2010) because the DNA isolation from the available herbarium material failed, but is described here as a new species. Lehtonen, sp.…”