132163 COMMON EVENING-PRIMROSE Oenothera biennis (Onograceae) Height to 1.5m. Downy biennial of waste land. FLOWERS are 4-5cm across, yellow and open only on dull days or evenings (Jun-Sep). FRUITS are capsules. LEAVES are lanceolate with red veins. STATUS-Introduced and naturalised. O.glaziovana (flowers 6-8cm across) and O.cambrica (flowers 3-5cm across) also occur; fruits have red, swollen-based hairs.