Contemporary taxonomists usually recognize a single species in Dumortiera, which is widely distributed through tropical and subtropical regions and extends into some temperate regions. Two subspecies, D. hirsuta subsp hirsuta and subsp. nepalensis, may be recognized, and both of these were thought to occur in Central America. We sequenced four loci, the nuclear internal transcribed spacer region ITS, and three chloroplast loci (rbcL, psbA-trnH and rpoC1) from 50 samples of Dumortiera across its geographic range to test for phylogenetic structure within the species and its congruence to morphological and geographic patterns. We also used light and scanning electron microscopy to examine morphological differences between accessions from Central America. Phylogenetic inferences reveal two highly distinct lineages: the first apparently restricted to Central America, and the second distributed across all the geographic regions sampled. This widespread lineage could itself be subdivided into several genetically and geographically distinct clades. The restricted Central American lineage contains plants that have a light green velvety appearance, due to an abundance of papillae on their upper thallus surface. These can therefore be distinguished morphologically from sympatric accessions of the widespread lineage, which are dark green, with a wide range of papillae densities (absent, few or abundant) on the thallus and usually with abundant marginal hairs. However, the wider application of these characters to lineages outside the Central American region has not yet been confirmed. We conclude that Dumortiera contains at least two, if not more, distinct species. The Asian epithet nepalensis does not seem applicable to plants in Central America, as the papillate morphotypes to which this name has been applied form an exclusively new world lineage. A thorough morphological revision of the genus, and reinvestigation of type material, is required.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.