Yellow iris  (Iris pseudacorus)

The yellow iris is a robust plant with beautiful bright yellow flowers (4). The roots and bulbs are thick and fleshy, and the narrow sword-shaped leaves are bluish-green with a prominent mid-rib (5). Between 4 and 12 large, showy flowers are borne on a somewhat flattened stem (5); they vary in colour from pale yellow to almost orange (2). An alternative name for this species is 'segg', which derives from an Anglo-Saxon word meaning 'short sword', and refers to the shape of the leaves (4). The fluttering of the flowers was thought to resemble flags blowing in the breeze, hence the name 'yellow flag' (6).