Burke: Hypericum majus vs. Hypericum perforatum

	Hypericum majus	Hypericum perforatum
	greater Canadian St. John's-wort	common St. John's-wort, Klamath weed
Habit	Perennial from short, leafy rhizomes, the stems upright, 1-5 dm. tall, simple or branched above.	Taprooted perennial with short rhizomes, the stems erect, 1-several, freely-branched, 3-8 dm. tall.
Leaves	Leaves opposite, sessile, lanceolate to oblong, rounded, 1-3.5 cm. long, 5- to 7-nerved.	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 terminal cymes with small, linear bracts; sepals 5, lanceolate, 4-7 mm. long; petals 5, yellow, about equal to the sepals; stamens 15-35, the filaments almost capillary, distinct; styles 3, short.	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 3-celled.	Capsule 5-8 mm. long, 3-celled, acute.

	Hypericum majus	Hypericum perforatum
Flowering time	July-September	June-July
Habitat	Peatlands, shores, damp sand, and cranberry farms.	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; British Columbia to Oregon, east to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]	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	Both native and introduced from eastern North America	Introduced from Europe
Conservation status	Sensitive in Washington (WANHP)	Not of concern
Sibling taxa	H. anagalloides, H. androsaemum, H. boreale, H. calycinum, H. canadense, H. ellipticum, H. maculatum, H. mutilum, H. perforatum, H. scouleri, H. tetrapterum	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 WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	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 majus

Hypericum perforatum

greater Canadian St. John's-wort

common St. John's-wort, Klamath weed

Habit

Perennial from short, leafy rhizomes, the stems upright, 1-5 dm. tall, simple or branched above.

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

Leaves

Leaves opposite, sessile, lanceolate to oblong, rounded, 1-3.5 cm. long, 5- to 7-nerved.

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 terminal cymes with small, linear bracts;

sepals 5, lanceolate, 4-7 mm. long;

petals 5, yellow, about equal to the sepals;

stamens 15-35, the filaments almost capillary, distinct;

styles 3, short.

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