Abstract Detail



Pteridology

Sundue, Michael [1], Triana-Moreno, Luz Amparo [2], Schwartsburd, Pedro [3].

New insights into the evolution of the fern family Dennstaedtiaceae.

We provide an update of our ongoing collaborative efforts to reconstruct the evolutionary history of the fern family Dennstaedtiaceae. Unlike most ferns which are shade-tolerant, Dennstaedtiaceae are prominent in open, disturbed, and edge habitats.  Among these is Pteridium, which aggressively colonizes open disturbed habitats and is, economically, among the worst damaging weeds in the world. What is not clear, however, is whether the predilection for these habitats is an ancient or derived condition. The ~270 species in the family are currently circumscribed within 10 genera. However, previous phylogenetic analyses indicate that Dennstaedtia might not be monophyletic. Most genera within the family are pantropical, or they are found on two out of the three main tropical landmasses. The family also includes examples of pantropical species, but neither their taxonomy nor biogeographic history has been thoroughly investigated. To address these questions, we compiled a data set of six plastid markers for 120 species and all ten recognized genera in the family. We also generated a chronogram calibrated with four fossils assignable to the family and outgroups and we reconstruct the history of 20 discrete morphological traits. Our results indicate that Dennstaedtia is paraphyletic with regards to Microlepia, Leptolepia, and Oenotrichia. Although we lack data from the type species, recircumscription of the genus is necessary. Within Hypolepis, we find support for geographically distinct clades, but many species groups appear to be complicated by hybridization. We also find evidence that favors splitting widespread pantropical species such as Histiopteris incisa more finely. Results from our dated phylogeny indicates that Dennstaedtiaceae have been occupying open niches since the end of the Cretaceous.


1 - The Pringle Herbarium, 111 Jeffords Hall, 63 Carrigan Dr., Burlington, VT, 05405, United States
2 - Universidad de Caldas, Departamento de Ciencias Biol├│gicas, Colombia
3 - Universidade Federal de Vi├žosa, Brazil

Keywords:
Cretaceous
Phyletic Slide
Bower
Shade-intolerant.

Presentation Type: Oral Paper
Session: PTER1, Pteridology I
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 10:45 AM
Number: PTER1004
Abstract ID:520
Candidate for Awards:None


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