Article · Wikipedia archive · Last revised Aug 5, 2026

Hypericum gymnanthum

Hypericum gymnanthum, the small-flowered St. John's wort or clasping leaf St. John's wort, is a species of flowering plant in the St. John's wort family Hypericaceae. It was first formally described in 1845.

Last revised
Aug 5, 2026
Read time
≈ 2 min
Length
379 w
Citations
14
Source
Wikipedia ↗
Hypericum gymnanthum
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Embryophytes
Clade: Tracheophytes
Clade: Spermatophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malpighiales
Family: Hypericaceae
Genus: Hypericum
Section: H. sect. Trigynobrathys
Subsection: H. subsect. Knifa
Species:
H. gymnanthum
Binomial name
Hypericum gymnanthum
Engelm. & Gray1
Synonyms1
  • Hypericum canadense var. cardiophyllum R.Keller
  • Hypericum mutilum var. gymnanthum (Engelm. & A.Gray) A.Gray
  • Sarothra gymnantha (Engelm. & A.Gray) Y.Kimura

Hypericum gymnanthum, the small-flowered St. John's wort2 or clasping leaf St. John's wort,3 is a species of flowering plant in the St. John's wort family Hypericaceae. It was first formally described in 1845.4

Description

H. gymnanthum ranges in height from 0.3 to 1 meters (approximately 1 to 3 feet) in height. Each yellow flower has five petals, each being 3 to 6 millimeters long.56 Its lower leaves are significantly smaller than its upper leaves, which are 1.5 centimeters long and 1 centimeter wide.6

Distribution and habitat

This species' range encompasses the eastern United States, from Florida to New York, and it also occurs in Guatemala.78 It has been introduced to Poland.7

It is commonly found in wet habitats such as sinkhole ponds, wet pine flatwoods, bogs, swales, and pine savannas.910 The United States Department of Agriculture classifies H. gymnanthum as a facultative wetland species.8

References

References

  1. "Hypericum gymnanthum Engelm. & Gray". Plants of the World Online. Royal Botanical Gardens Kew. Retrieved 20 December 2018.
  2. Robson, Norman K. B. (2015). "Hypericum gymnanthum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 6. New York and Oxford: Oxford University Press. Retrieved 20 December 2018 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  3. "Hypericum gymnanthum Species Page". floraofalabama.org. APA: Alabama Plant Atlas. Retrieved 20 December 2018.
  4. "Hypericum gymnanthum Engelm. & Gray". ipni.org. International Plant Names Index. Retrieved 20 December 2018.
  5. "Lady Bird Johnson Wildflower Center - The University of Texas at Austin". www.wildflower.org. Retrieved 2025-08-01.
  6. Godfrey, Robert K. (1981). Aquatic and Wetland Plants of Southeastern United States: Dicotyledons. Jean W. Wooten. Athens: University of Georgia Press. ISBN 978-0-8203-0532-5.
  7. "Hypericum gymnanthum Descriptions". hypericum.myspecies.info. Retrieved 20 December 2018.
  8. "USDA Plants Database". plants.usda.gov. Retrieved 2025-08-01.
  9. Weakley, A. S. (2015). Flora of the Southern and Mid-Atlantic States. Chapel Hill, NC, University of North Carolina Herbarium.
  10. "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 2025-08-01.