St. John's-wort

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St. John's-wort inflorescence

St. John's-wort leaves

St. John's-wort

St. John's-wort flowers

St. John's-wort

St. John's-wort

St. John's-wort

St. John's-wort fruit

St. John's-wort

St. John's-wort flowers

St. John's-wort flowers

St. John's-wort habit

St. John's-wort

St. John's-wort

St. John's-wort

St. John's-wort

St. John's-wort leaves

Morphology

Stem

Erect, several to many, often branched, ridged, glabrous, reddish.

Leaves

Opposite, simple, sessile, oblong to linear, .5 to 1.5 inch long, less than 1/3 inch wide, glabrous, glandular-dotted; margins entire, rolling downward; tips pointed to rounded; upper leaves reduced.

Inflorescence

Cymes, densely flowered, leafy-bracted, terminal.

Flower

Sepals 5, linear-lanceolate, unequal; corollas 3/4 to 1 inch wide, petals 5, to 1/2 inch long, bright yellow to orange-yellow, margins black-dotted; stamens numerous, in 3 clusters.

Fruit

Capsules, egg-shaped, to 3/4 inch long; seeds small, pitted, black or dark brown.

Ecology

Habitat

Prairies, pastures, waste areas, and roadsides, most abundant in sandy soils.

Distribution

Throughout except southwest corner of Kansas.

Practical Information

Toxicity

Plants contain hypericin, which causes a photosensitive reaction following ingestion. This toxic reaction can be fatal to sheep and goats, which readily graze the plant.

Uses

Native Americans used St. John's-wort to treat fevers, coughs, intestinal problems, nosebleeds, and snakebites.

Additional Notes