title: Why are there so few species of ferns?
abstract: A recent study has documented a natural hybridization event between two fern lineages that last shared a common ancestor about 60 million years ago. This is one of the deepest hybridization events ever described and has important implications for plant speciation theory.
authors.affiliation: Department of Botany, University of Hawai'i at Mānoa, 3190 Maile Way, Honolulu, HI 96822, USA. Electronic address: tom.ranker@gmail.com.
authors.forename: Tom A
authors.initials: TA
authors.lastname: Ranker
authors.affiliation: Department of Botany, University of Hawai'i at Mānoa, 3190 Maile Way, Honolulu, HI 96822, USA; The Pringle Herbarium, Department of Plant Biology, The University of Vermont, 27 Colchester Ave., Burlington, VT 05405, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sundue
mesh_terms: D029624:Ferns / Q000145:classification*; D006824:Hybridization, Genetic; D013045:Species Specificity
keywords: deep hybridization; ferns; gene flow; speciation