| 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. | |