Hypericum lissophloeus

Common Name: smoothbark St. Johnswort  
Type: Broadleaf evergreen
Family: Hypericaceae
Native Range: Florida
Zone: 7 to 9
Height: 6.00 to 10.00 feet
Spread: 3.00 to 5.00 feet
Bloom Time: July to August
Bloom Description: Yellow
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Showy
Leaf: Evergreen
Other: Winter Interest
Tolerate: Drought, Wet Soil

Culture

Easily grown in moist but well-drained soils in full sun. Tolerates part shade. Also tolerates periods of flooding and standing water as well as periods of drought.

Noteworthy Characteristics

Hypericum lissophloeus, commonly known as smooth-barked St. Johnswort, is a narrow, upright, sparsely-branched, asparagus-like evergreen shrub with a tree-like character that typically grows to 6-10’ tall and to 3-5’ wide. It is native to well-drained sandy soils on the slopes and margins of sink hole ponds and lakes located in an area of xeric uplands in Bay and Washington Counties on the Florida panhandle. It is listed as an endangered species in the State of Florida. Dramatic water fluxuations occur in the areas of these sink holes during the course of a year ranging from periodic episodes of drought to swampy conditions including seasonal flooding with standing water to as much as 4’ deep. Shrubs growing in water often develop woody interlaced prop roots. Distinguishing features of this shrub include (1) smooth chestnut brown exfoliating bark, (2) needle-like gray-green leaves (to 1” long), (3) 5-petaled bright yellow flowers (to 1/ 2” across) which bloom in summer in 1-3 flowered inflorescences, and (4) multi-seeded capsules.

Genus name comes from the Greek words hyper meaning above and eikon meaning picture in reference to the practice of hanging flowers from this genus above images, pictures or windows.

Specific epithet comes from the Greek words lisso meaning smooth and phloeus meaning bark in commemoration of the bark found on this shrub which triggered adoption of the “smooth-barked” part of the common name.

Problems

No serious insect or disease problems. Watch for rust. Powdery mildew may occur.

Uses

Lacy background plant. Native plant gardens.