Triadenum walteri (J. G.Gmel.) Gleason

Locations ofTriadenum walteri (J. G.Gmel.) Gleason in Virginia

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Botanical Name
Triadenum walteri (J. G.Gmel.) Gleason
Common Name
Greater Marsh St. John's-wort
Hypericum walteri Gmelin
Flora of Virginia Name/Status
Triadenum walteri (J. G.Gmel.) Gleason
The proper disposition of plants in the genus Triadenum may be still unresolved, as they have been recently treated in both Hypericum and Triadenum. Based on a comprehensive phylogenetic study of Hypericum (sensu lato), Nürk et al. (2013, Molec. Phylogen. & Evol. 66: 1-16) included Triadenum in Hypericum, but the position of Triadenum as a somewhat basal clade and the inclusion of Triadenum japonicum suggests that the fairly ancient, eastern North American - east Asian vicariance had elements that were clearly similar to one another and distinct from other Hypericums long ago. The morphological distinctions of Triadenum lend further credence to its treatment as a separate genus.
Alluvial, tidal, and maritime swamp forests; floodplain pools and ponds, depression ponds and swamps, shrubby interdune ponds, freshwater tidal marshes. Common in the Coastal Plain, infrequent in the outer Piedmont; rare in the mountains.
Native Status

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