Hypericum tenuifolium

Hypericum tenuifolium
Conservation status
Secure  (NatureServe) [1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Malpighiales
Family:	Hypericaceae
Genus:	Hypericum
Section:	H. sect. Myriandra
Subsection:	H. subsect. Centrosperma
Species:	H. tenuifolium
Binomial name
Hypericum tenuifolium Pursh [2]
Synonyms [3]
Hypericum corisWalter Hypericum fasciculatum var. laxifoliumChoisy Hypericum galioides var. reductumSvenson Hypericum reductum(Svenson) P.B.Adams

Hypericum tenuifolium, known as Atlantic St. John's-wort ^[4] and sandhill St. John's-wort, ^[5] is a species of flowering plant in the St. John's wort family, Hypericaceae. It is endemic ^[1] to the Southeastern United States. ^[6]

Description

Atlantic St. John's-wort is a small, spreading shrub, growing 10–50 cm (3.9–19.7 in) tall and forming mats. ^{[6] [7]} The leaves are very narrow, hence its name tenuifolium (from Latin tenuis 'thin'and folium 'leaf'), and are only 0.4–0.8 mm (0.016–0.031 in) broad and 4–11 mm (1⁄8–3⁄8 in) long, with rounded tips and revolute margins. The flowerheads are narrowly cylindric, producing 1-7 flowers. Each flower is 10–14 mm (3⁄8–1⁄2 in) broad with 5 sepals, 5 bright yellow petals, and 50-90 stamens. The ovaries are three-parted, forming cylindric capsule fruits. It flowers in the summer, typically June through September, but sometimes as late as December. ^[5]

Distribution and habitat

Hypericum tenuifolium occurs in the Atlantic coastal plain in the southeastern United States, in Alabama, Florida, Georgia, North Carolina, and South Carolina. ^[6] Its habitat includes dry, open, sandy areas such as pine flatwoods, pine savannas, and sandhills. ^{[6] [5]}

References

1. "Hypericum reductum". NatureServe Explorer. Retrieved 31 May 2025.
2. "Hypericum tenuifolium Pursh". ipni.org. International Plant Names Index. Retrieved 2018-10-13.
3. "Hypericum tenuifolium Pursh". Plants of the World Online. Royal Botanical Gardens Kew. Retrieved 2018-10-13.
4. NRCS. "Hypericum tenuifolium". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 2018-10-13.
5. Weakley, Alan S. (2018), Flora of the Southern and Mid-Atlantic States, working draft of 20 August 2018, University of North Carolina Herbarium, North Carolina Botanical Garden, University of North Carolina at Chapel Hill
6. Robson, Norman K. B. (2015). "Hypericum tenuifolium". 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 2018-10-13– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
7. "Hypericum tenuifolium". hypericum.myspecies.info. Retrieved 2018-10-13.