Abstract Detail

The power of two: Marrying phylogeny and biogeography to reconstruct the evolutionary history of pteridophytes

Rouhan, G. [4], Dubuisson, Y.-I. [4], Rakotondrainibe, F. [3], Motley, Timothy J. [2], Mickel, J. T. [1], Moran, Robbin [1].

Molecular phylogeny of Elaphoglossum (Elaphoglossaceae) and relationships between species from the Neotropics and the African-Indian Ocean area.

We performed a phylogenetic analysis of Elaphoglossum using two non-coding chloroplast spacers: trnl-trnF and rps4-trnS. The sampling includes 123 species from the Neotropics, Africa, and the Indian Ocean area. The results largely agree with a previous classification based on morphology by Mickel and Atehortúa (1980). Within the genus are four large species-rich clades: sect. Elaphoglossum often with thick glabrous or sparsely scaled blades; sect. Squamipedia small species with long-creeping rhizomes, echinulate spores, and paired peglike aerophores on the rhizome; sect. Lepidoglossa often with conspicuously scaly blades, and a “subulate-scaled clade” consisting of sects. Setosa (hydathodous) and Polytrichia (non-hydathodous). Section Amygdalifolia, which consists of the sole species E. amygdalifolia is sister to the rest of the genus. Using the phylogeny as a framework, we assess the relationships of species from Africa and the Indian Ocean region with those from the Neotropics. Out of the 11 sister-species postulated by Moran and Smith (2001) on the basis of morphology, two are well supported (E. eximium - E. aubertii; E. piloselloides-E. spathulatum) and three are not supported (E. ciliatum – E. humbertii; E. muscosum – E. poolii; E. paleaceum – E. deckenii). The latter are interpreted as examples of remarkable morphological convergences. Our molecular markers were not variable enough for resolving two sister-species relationships (E. erinaceum – E. hybridum; E. glabellum – E. acrostichoides). Four sister-species could not be tested because specimens were lacking. Two additional sister-species are proposed: E. cuspidatum – E. succisaefolium; E.doanense – E. hornei. Placement of the species from the Indian Ocean suggests that at least 21 long distance dispersal events occurred between the Neotropics and the African-Indian Ocean region.

1 - New York Botanical Garden, Institute of Systematic Botany, 200th St & Kazimiroff Blvd, Bronx, New York, 10458, USA
2 - New York Botanical Garden, Cullman Program for Molecular Systematics Studies, 200th St. & Southern Blvd., Bronx, New York, 10458-5126, USA
3 - Museum National d'Histoire Naturelle,, Ecole Pratique des Hautes Etudes,, 16 rue Buffon,, 75005, Paris, , France
4 - Universite Pierre et Marie Curie,, Laboratoire de Paléobotanique et Paléoécologie,, 12 rue Cuvier,, 75005, Paris, , France

Keywords:
biogeography
geographical distribution
molecular data
phytogeography
ferns
Elaphoglossum
long-distance dispersal
neotropics
Africa.

Presentation Type: Symposium
Session: 34-5
Location: Ballroom 1 (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 4:30 PM
Abstract ID:215