131549 SQUARE-STALKED ST JOHN’S-WORT Hypericum tetrapterum (Clusiaceae) Height to 1m. Upright, hairless perennial. Similar to Imperforate St John’s-wort but the square stems are distinctly winged. Found in damp ground. FLOWERS are 2cm across with yellow petals and undotted, pointed sepals (Jun-Sep). FRUITS are dry capsules. LEAVES are oval with translucent dots. STATUS-Widespread and locally common, except in the N.