Hypericum tenuifolium

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]

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 coris Walter Hypericum fasciculatum var. laxifolium Choisy Hypericum galioides var. reductum Svenson Hypericum reductum (Svenson) P.B.Adams

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]