Square-Stalked St. John’s Wort
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(Hypericum tetrapterum)
Square-Stalked St. John’s Wort (Hypericum tetrapterum)
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© Carlos Franquinho
CC BY-SA 4.0
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© Carlos Franquinho
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Copyright:
CC BY-SA 4.0
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Photo by: © Carlos Franquinho | License Type: CC BY-SA 4.0 | License URL: http://creativecommons.org/licenses/by-sa/4.0/ | Uploader: franquinho | Publisher: iNaturalist |
Summary
Hypericum tetrapterum, commonly known as Square-stalked St. John’s Wort, is a rhizomatous perennial herb native to wetlands and riparian zones across Europe. It typically grows to a height of up to 3 feet 11 inches and is characterized by its square stems and leaves with translucent glandular dots. The plant is notable for its pale yellow flowers, which are adorned with conspicuous black glands and bloom in dense cymes of up to 70 flowers during the summer months. The flowers are relatively showy and attract a variety of pollinators.
Square-stalked St. John’s Wort is valued for its medicinal properties and is often used in traditional herbal remedies. In cultivation, it is appreciated for its ability to thrive in damp conditions and is commonly used in water gardens, rain gardens, and as a ground cover in moist, shaded areas. It prefers consistently moist soil, partial shade to full sun, and can tolerate a range of soil types provided they are well-drained. While generally low-maintenance, it can be susceptible to rust and leaf spot diseases. Gardeners should be aware that in some regions, it can spread aggressively and may require management to prevent unwanted naturalization.CC BY-SA 4.0
Square-stalked St. John’s Wort is valued for its medicinal properties and is often used in traditional herbal remedies. In cultivation, it is appreciated for its ability to thrive in damp conditions and is commonly used in water gardens, rain gardens, and as a ground cover in moist, shaded areas. It prefers consistently moist soil, partial shade to full sun, and can tolerate a range of soil types provided they are well-drained. While generally low-maintenance, it can be susceptible to rust and leaf spot diseases. Gardeners should be aware that in some regions, it can spread aggressively and may require management to prevent unwanted naturalization.CC BY-SA 4.0
Plant Description
- Plant Type: Herb
- Height: 1.5-2.5 feet
- Width: 1-1.5 feet
- Growth Rate: Moderate
- Flower Color: Yellow
- Flowering Season: Summer
- Leaf Retention: Deciduous
Growth Requirements
- Sun: Full Sun, Part Shade
- Drainage: Medium, Slow
Common Uses
Low Maintenance, Water Garden
Natural Habitat
Wetlands and riparian zones across Europe
Other Names
Common Names: Square-stalked St John’s Wort, Four-angled St John’s Wort
Scientific Names: Hypericum tetrapterum, Holosepalum quadrangulum, Hypericum acutum, Hypericum acutum f. humile, Hypericum acutum f. patulum, Hypericum acutum subsp. corsicum, Hypericum acutum subsp. tetrapterum, Hypericum acutum subsp. tetrapterum, Hypericum acutum var. anagallidioides
GBIF Accepted Name: Hypericum tetrapterum