| Triadenum | |
|---|---|
 | |
| Triadenum virginicum | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Hypericaceae |
| Tribe: | Cratoxyleae |
| Genus: | Triadenum Raf. |
| Type species | |
| T. fraseri (Spach) Gleason | |
| Synonyms[1] | |
| |
Triadenum, known asmarsh St. John's worts,[2] is a smallgenus offlowering plants in thefamilyHypericaceae. The genus is characterized by opposite, blunt-tipped leaves and pink flowers with 9stamens. They are distributed in North America and eastern Asia.
Acceptance of this genus is varied.Kew'sPlants of the World Online[3] and the Database of Vascular Plants of Canada (VASCAN)[4] treat it as a junior synonym ofHypericum and theFlora of North America[1] andFlora of China[5] treat it as separate. The situation arises from B. R. Ruhfel et al. (2011)'s genetic study describingTriadenum as subsumed underHypericum and later genetic results disagreeing with this assessment.[6] UnderHypericum, the species are mostly treated as the sectionHypericum sect.Elodea.[7]
Triadenum contains the following 6 species according toFlora of North America andFlora of China:[1][5]
Triadenum species | |||
|---|---|---|---|
 |  | ||
| National | |
|---|---|
| Other | |
