Hypericum Tetrapterum - (Square-stem St John's Wort) 1 ltr

Hypericum tetrapterum (Square-stalked St John's Wort) is a native, rhizomatous perennial found in wet, fertile habitats like marshes, ditches, and riverbanks. It grows 25-100 cm tall, featuring distinct, four-winged square stems, opposite ovate leaves with translucent glands, and clusters of pale yellow, 1cm flowers from July to September. 

Key Characteristics and Growth
Appearance: Erect, hairless, and sometimes spreading habit with a woody base.
Stems: Rigidly square with four prominent, wing-like ridges, often reddish-tinged.

Leaves: Small, opposite, oval-shaped (ovate to orbicular) leaves, featuring translucent dots (glands) and occasionally black dots.

Flowers: Pale yellow, 5-petaled flowers, measuring 9-13 mm in diameter, arranged in dense, flat-topped clusters.

Habitat: Thrives in damp, boggy, or marshy soils and can be used in shallow water pond margins (up to 5cm deep).

Maintenance: Low-maintenance, fully hardy perennial. It spreads via rhizomes, making it suitable for naturalizing in damp areas. 

This plant is often confused with other Hypericum species, but the pronounced wings on the stem are its identifying feature.