Ireland Post issued the sixth definitive stamp series of Wildflowers of Ireland on March 1, 2007. The issue comprises of four postage stamps with denomination value 3c, 55c, 78c, and 95c.
The species of wildflower depicted are Yellow flag (Iris pseudacorus) on the 3c stamp, Large-flowered butterwort (Pinguicula grandiflora) on the 55 c stamp, Black bog-rush (Schoenus nigricans) on the 78 c stamp, Lythrum salicaria (Purple loosestrife) on the 95 c stamp.
Yellow flag or Iris pseudacorus is an herbaceous flowering perennial plant, native to Europe, western Asia and northwest Africa, growing to 1-1.5 m (or a rare 2 m) tall, with erect leaves up to 90 cm long and 3 cm broad. The flowers are bright yellow, 7-10 cm across, with the typical iris form.
The fruit is a dry capsule 4-7 cm long, containing numerous pale brown seeds. Yellow flag is a species in the genus Iris, of the family Iridaceae.
