Molecular studies of representative species in the fern genus Elaphoglossum (Dryopteridaceae) based on cpDNA sequences rbcL, trnL-F, and rps4-TRNS

• Published in: International journal of plant sciences Vol. 165; no. 6; pp. 1063 - 1075
• Main Authors: Skog, J.E, Mickel, J.T, Moran, R.C, Volovsek, M, Zimmer, E.A
• Format: Journal Article
• Language: English
• Published: Chicago The University of Chicago Press 01-11-2004; University of Chicago, acting through its Press
• Subjects: Biodiversity; Botany; chloroplast DNA; Dryopteridaceae; Elaphoglossum; Ferns; ferns and fern allies; Molecular biology; molecular systematics; phylogeny; plant genetics; sequence analysis; chloroplast genes; Dryopteridaceae; Pteridophyta; ferns; molecular systematics; Elaphoglossum
• ISSN: 1058-5893; 1537-5315
• DOI: 10.1086/423877

Phylogenetic relationships among 48 species representing the nine sections within the fern genus Elaphoglossum were investigated using cpDNA sequence data from rbcL, trnL-F, and rps4-trnS. Elaphoglossum is shown to be a well-supported, monophyletic genus containing five major clades. Mapping of morphological characters onto the molecular phylogeny reveals how scale structure, rhizome morphology, presence/absence of hydathodes and/or phyllopodia, and general growth form are important synapomorphies for sectional and subsectional classification in Elaphoglossum. The first major clade is formed by species with subulate scales and/or hydathodes. Within this clade, a monophyletic group is formed by those species possessing hydathodes, and another monophyletic group is formed by species lacking hydathodes. The second major clade is formed by species that generally have conspicuously scaly blades. The third major clade is characterized by slender, long-creeping, two-ranked rhizomes, small leaves (generally less than 20 cm long), and echinulate spores. The fourth clade has phyllopodia and inconspicuously scaly or glabrous blades but is separated in two subgroups, one consisting of small plants with short- to long-creeping rhizomes and another of relatively larger plants with thicker, more congested rhizomes. The fifth clade consists solely of Elaphoglossum amygdalifolium, which differs from all other members of the genus by the combination of long-creeping rhizomes, hydathodes, phyllopodia, and reddish young leaves. Hydathodes have evolved independently more than once in Elaphoglossum.