Photographs: Foynes, Co. Limerick

Hoary Mustard Hirschfeldia incana Mustard liath Family: Brassicaceae Flowering: May-October. Annual or short-lived perennial. Introduced. Long racemes of pale-yellow flowers that over-top the buds. Erect, adpressed fruit with a swollen beak. One seed in beak. Coarse-toothed, grey-green leaves are deeply pinnate lobed, terminal lobe largest. Stem leaves are narrow-lanceolate. Leaves usually hairless above and downy underneath. Stems white-pubescent below with stiff short hairs. To 1.2m Established in Dublin, a rare casual elsewhere in Ireland on dry waste ground, roadsides and in urban areas

Hoary Mustard, Hirschfeldia incana, Mustard liath