Hypericum Linnaeus. St. John's-wort.
A genus of 370-420 species, trees, shrubs, and herbs, primarily temperate. Hypericum in our area is a large, complex, and interesting genus, with a number of unresolved questions remaining. The species treated in Key B have often been treated in the segregate genus Ascyrum; evidence from a variety of disciplines now suggests that they should be included in Hypericum (Adams & Robson 1961; Calie, Schilling, & Webb 1983; Robson 1996; Nürk et al. 2013). Triadenum is almost basal in (or to) Hypericum, and its inclusion in Hypericum has also been recently promoted (e.g. Nürk et al. 2013), but its retention at generic rank is suggested by its morphological distinction and position as a basal clade.
ID notes: “Longest leaves” should be sought at branch nodes.
Ref: Adams (1957); Adams (1962); Adams (1973); Adams & Robson (1961); Allison (2011); Calie, Schilling, & Webb (1983); Cooperrider (1989); Culwell (1970); Godfrey (1988); Meseguer et al. (2015); Meseguer, Aldasoro, & Sanmartín (2013); Nürk et al. (2013); Robson (1985, 1990, 2001, 2002, 2006); Robson (1996); Robson (2015a) In Flora of North America Editorial Committee (2015); Robson & Adams (1968); Sorrie (2012); Stevens In Kubitzki, Bayer, & Stevens (2007); Weakley et al. (2011); Webb (1980). Show full citations.