Molecular phylogenetic species delimitation in the aquatic genus Ottelia (Hydrocharitaceae) reveals cryptic diversity within a widespread species.

Ottelia, a pantropical genus of aquatic plants belonging to the family Hydrocharitaceae, includes several narrowly distributed taxa in Asia. Although the Asian species have received comparatively more research attention than congeners in other areas, various key taxonomic questions remain unaddressed, especially with regards to apparent cryptic diversity within O. alismoides, a widespread species complex native to Asia, northern Australia and tropical Africa.

(Araceae): New palynological insights with special regard to its controversial systematic position and to closely related genera.

Almost all systematic treatments agree that is a puzzling case, being a highly autapomorphic taxon with obscure relationships. In molecular-based classifications the variable placements of within Aroideae conflict strongly with those in morphologically and anatomically based systematic classifications, which treat the genus as a subfamily (Calloideae) of its own. We studied the pollen morphology and ultrastructure of by light and electron microscopy, and mapped the relevant pollen characters as well as some flower characters to the proposed placements of within the Araceae as indicated in the various molecular phylogenies.

Relationships within the Araceae: comparison of morphological patterns with molecular phylogenies.

Premise Of The Study: The first family-wide molecular phylogeny of the Araceae, a family of about 3800 published species in 120 genera, became available in 1995, followed by a cladistic analysis of morpho-anatomical data in 1997. The most recent and comprehensive family-wide molecular phylogeny was published in 2008 and included species from 102 genera. We reanalyzed the molecular data with a more complete genus sampling and compared the resulting phylogeny with morphological and anatomical data, with a view to contributing to a new formal classification of the Araceae.

Phylogenetic relationships of aroids and duckweeds (Araceae) inferred from coding and noncoding plastid DNA.

Familial, subfamilial, and tribal monophyly and relationships of aroids and duckweeds were assessed by parsimony and Bayesian phylogenetic analyses of five regions of coding (rbcL, matK) and noncoding plastid DNA (partial trnK intron, trnL intron, trnL-trnF spacer) for exemplars of nearly all aroid and duckweed genera. Our analyses confirm the position of Lemna and its allies (formerly Lemnaceae) within Araceae as the well-supported sister group of all aroids except Gymnostachydoideae and Orontioideae. The last two subfamilies form the sister clade of the rest of the family.