Specimen record

Common St. John's Wort

Hypericum perforatum

Description

A naturalized perennial from Europe that blooms prolifically along roadsides and in dry meadows in early to mid-July, traditionally around the feast of St. John the Baptist (June 24). The bright yellow flowers have a distinctive feature: dark glandular dots along the petal margins that release a red pigment (hypericin) when crushed. The leaves, when held up to light, show translucent dots — oil glands that give the species its name 'perforatum.'

Identification tips

• 1Bright yellow 5-petaled flowers with black dots along petal margins
• 2Leaves with translucent dots visible when held up to sunlight (perforated appearance)
• 3Opposite, sessile, oblong leaves on a round two-ridged stem
• 4Numerous stamens in 3 clusters giving flowers a brushy center
• 5Grows 30–90 cm tall in dry, sunny roadsides and disturbed ground