Burke: Hypericum perforatum

	Hypericum perforatum
	common St. John's-wort, Klamath weed
Habit	Taprooted perennial with short rhizomes, the stems erect, 1-several, freely-branched, 3-8 dm. tall.
Leaves	Leaves opposite, sessile, narrowly spatulate-oblanceolate to lanceolate, 1-3 cm. long, dotted with purplish-black, not clasping, but connected by narrow, wing-like structures at the base.
Flowers	Inflorescence of large, many-flowered, leafy-bracteate, compound cymes; sepals 5, lanceolate, acute, 5-7 mm. long; petals 5, yellow, about twice as long as the sepals, their margins with conspicuous, black spots; stamens 75-100, attached at the base into 3 distinct groups; styles 3.
Fruits	Capsule 5-8 mm. long, 3-celled, acute.

	Hypericum perforatum
Flowering time	June-July
Habitat	Noxious weed of fields, meadows, roadsides, forest edge, wastelots, and other disturbed areas from the lowlands to near subalpine.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Europe
Conservation status	Not of concern
Sibling taxa	H. anagalloides, H. androsaemum, H. boreale, H. calycinum, H. canadense, H. ellipticum, H. maculatum, H. majus, H. mutilum, H. scouleri, H. tetrapterum
Subordinate taxa	H. perforatum ssp. perforatum
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Hypericum perforatum

common St. John's-wort, Klamath weed

Habit

Taprooted perennial with short rhizomes, the stems erect, 1-several, freely-branched, 3-8 dm. tall.

Leaves

Leaves opposite, sessile, narrowly spatulate-oblanceolate to lanceolate, 1-3 cm. long, dotted with purplish-black, not clasping, but connected by narrow, wing-like structures at the base.

Flowers

Inflorescence of large, many-flowered, leafy-bracteate, compound cymes;

sepals 5, lanceolate, acute, 5-7 mm. long;

petals 5, yellow, about twice as long as the sepals, their margins with conspicuous, black spots;

stamens 75-100, attached at the base into 3 distinct groups;

styles 3.

Fruits

Capsule 5-8 mm. long, 3-celled, acute.