Scientific Name: Hypericum perforatum
Common Name: St. John's wort
Family Name: Hypericaceae
Origin: Africa - northern, Central / west Asia, Europe, S.E. Asia / Japan / China
Hardiness Zone: Zone 4: (-34 to -29 °C)
Plant Type: Herbaceous perennial, Invasive plant
Mature Size: 0.7 - 1.3m x 0.3 - 0.6m (height x width)
Habit: Stiffly upright
Form: Oval - vertical
Texture: Fine
Landscape Uses: Medicinal plant
Exposure: Full sun
Soil or Media: Rocky or gravelly or dry, Well-drained
Leaves: Simple, Opposite, Sessile, Soft flexible, Pinnate venation, Glabrous, Lanceolate, Oblanceolate, Oblong, Entire
Flowers: Cyme, Yellow, Aug-Sep-Oct
Fruit: Capsule, Brown, Sep-Oct
Key ID Features:
Upright, highly branched stems 10-100cm tall; rhizomes; leaves sessile, opposite, lanceolate-oblanceolate, most 1-3cm long x 0.5-1.5cm wide, glabrous, when held up to light small clear dots or perforations can be seen, black marginal dots; corymb-like cyme, flowers ~3cm wide, bight yellow, 5 petals, 8-10mm long, many stamens; capsules 5-8mm long.