Topas
St. John's Wort(Hypericum perforatum)
A European-bred medicinal selection of Hypericum perforatum noted for high, comparatively stable production of hypericin and flavonoids such as hyperoside and rutoside; historically among the most widely cultivated commercial St. John's Wort varieties. It closely resembles the wild species in appearance but is distinguished by its elevated content of the active medicinal naphthodianthrones.
Visual Characteristics
Grows roughly 1-3 ft (30-90 cm) tall with star-shaped, 5-petaled yellow flowers borne in pyramidal compound cymes in summer (June-August); petals are peppered with black glandular dots and the flower centers carry a boss of yellow stamens.
Growing Tips
Grown commercially in full sun on well-drained soil for pharmaceutical hypericin production; harvest at full flowering when hypericin content peaks.
Resistance Information
Disease Resistance
Susceptible to the fungal pathogen Colletotrichum gloeosporioides (anthracnose), which has been a significant problem in dense plantings.
Where to Buy
Sourcing information coming soon. Check local nurseries and seed banks for availability.