OF THE CAROLINAS & GEORGIA

Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Rosids: Fabids: Malpighiales

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Hypericum perforatum   FAMILY Hypericaceae   Go to FSUS key



SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Hypericum perforatum   FAMILY Clusiaceae

SYNONYMOUS WITH Flora of North America

Hypericum perforatum ssp. perforatum

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 126-01-026:

Hypericum perforatum   FAMILY Hypericaceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)

Hypericum perforatum

 

COMMON NAME:
European St. Johnswort, Common St. Johnswort, Klamath-weed


         To see larger pictures, click or hover over the thumbnails.

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913    pnd_hype_001_lvd

        

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

USDA / Selected Weeds of the US. 1970    swus_page_267

        

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

Tim Spira    tpshperforatum2

June        

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

Tim Spira    tpshperforatum2_2

June        

Leaves sessile, with translucent dots that look like "windows", per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

JK Marlow    jkm090707_010

July    Avery County    NC

The Roan Highlands

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

JK Marlow    jkm090707_015

July    Avery County    NC

The Roan Highlands

Numerous flowers borne in a compound cyme, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

JK Marlow    jkm090707_016

July    Avery County    NC

The Roan Highlands

Flowers 3/4"-1" wide, with black "stitching" on the margins of petals, per Wildflowers of the Southern Mountains (Smith, 1998).

image of Hypericum perforatum, European St. Johnswort, Common St. Johnswort, Klamath-weed

JK Marlow    jkm090707_020

July    Avery County    NC

The Roan Highlands

Five petals, to 0.4" long, black-dotted near the margin, per Wildflowers of Tennessee (Carman, 2005).

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Hypericum perforatum   FAMILY Hypericaceae

SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Hypericum perforatum   FAMILY Clusiaceae

SYNONYMOUS WITH Flora of North America
Hypericum perforatum ssp. perforatum

SYNONYMOUS WITH VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 126-01-026:
Hypericum perforatum   FAMILY Hypericaceae

SYNONYMOUS WITH Manual of the Southeastern Flora (Small, 1933, 1938)
Hypericum perforatum

 

Find by SCIENTIFIC NAME:

725

Forb
Perennial

Habitat: Fields, pastures, roadsides, woodland borders, per Weakley's Flora

Non-native: Europe

Common (rare in Coastal Plain)

map
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.

Click here to see a map showing all occurrences known to SERNEC, a consortium of southeastern herbaria. (Zoom in to see more detail.)


Invasive?

This plant may be causing problems in natural areas outside its native range, according to authorities such as:

 

LEAVES:
Simple
Opposite

FLOWER:
Summer/Fall
Yellow
Radially symmetrical
5 persistent sepals
5 petals
Superior ovary
Bisexual

FRUIT:
Summer/Fall
Capsule

 

TO LEARN MORE about this plant, look it up in a good book!



 


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