Epimedium acuminatum
Common Name: bishop's hat
Type: Herbaceous perennial
Family: Berberidaceae
Native Range: Western and central China
Zone: 5 to 9
Height: 1.00 to 2.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: April to May
Bloom Description: Purplish and white
Sun: Part shade to full shade
Water: Dry to medium
Maintenance: Low
Suggested Use: Ground Cover, Naturalize
Flower: Showy
Leaf: Evergreen
Other: Winter Interest
Tolerate: Rabbit, Deer, Drought, Heavy Shade, Erosion, Dry Soil, Shallow-Rocky Soil

Culture

Easily grown in average, acidic, dry to medium moisture, well-drained soils in part shade to full shade. Prefers loose, organically rich loams with consistent moisture in part shade (sun-dappled or morning sun). Foliage will usually burn in full afternoon sun. Tolerates full shade. Also tolerates drought and dry shade (rhizomes hold moisture) once established. Intolerant of alkaline soils. Clumps spread somewhat slowly by creeping rhizomes, but will form attractive colonies over time. Foliage is evergreen south of USDA Zone 7 but basically deciduous in the St. Louis area. As needed, cut back any remaining old foliage in late winter prior to the emergence of the new growth. Propagate by division in early spring or fall.

Noteworthy Characteristics

Epimedium acuminatum is noted for its attractive narrow green leaflets with acuminate tips and its large, spider-type, purple and white spring flowers. It is a rhizomatous perennial that typically grows on wiry stems to form a clump rising to 12" tall spreading to 18" wide. It is native to alpine woodlands in western and central China (Guizhou, Yunnan and Sichuan Provinces). Showy, spidery, nodding, long-spurred, columbine-like, purple and white flowers (1-2" across) bloom in compound inflorescences (10-55 flowers per inflorescence) in spring (April-May) atop flowering stems rising above the foliage to 24" tall. Each flower features four showy spurred purple petals and eight sepals (four petal-like ovate-elliptic white inner sepals and four much smaller light purple outer sepals which drop at the time of bloom). Each flowering stem bears two opposite trifoliate leaves. Leaves are basal and cauline, usually with biternate but sometimes triternate leaflets. Leaflets (to 4-7" long) are narrow and ovate to lanceolate with spiny marginal teeth and cordate bases. New leaves emerge in spring with a pink-maroon cast, but mature to medium to dark green. Leaves form attractive foliage mounds.

Genus name is of unclear origin and meaning but the Greeks used epimedion for a very different plant.

Specific epithet means tapering into a long narrow point.

Epimediums are commonly called bishop’s hat or bishop's mitre (four-spurred flowers of some species resemble a clergyman's biretta) or barrenwort (root extract was once believed to prevent female conception).

Problems

No serious insect or disease problems. Mosaic virus (transmitted by aphids) is the main disease problem.

Garden Uses

Ground cover or edger for shady areas. Mass in woodland gardens, wild gardens or naturalized areas. Also effective in partially shaded areas of rock gardens and border fronts. Grows well under trees. Edger for paths and walkways.