Commonly seen along our motorways and in dry, lime-rich disturbed ground, this is a tall biennial which reaches over 1 metre high. It has small yellow-green flowers (4-5mm across) which are borne in long, dense, tapering spikes on hollow stems in the plant's second year. Each little flower has 4 divided petals, 4 sepals and blooms from June to August. The leaves are narrow and in the first year of the plant's life they form a basal rosette; in the second year there are lanceolate stem leaves with wavy edges. This is a native wildflower and it belongs to the family Resedaceae.
While waiting for a train at Dalkey Railway Station, Co Dublin in 2007 I saw this plant and wondered what it was. I came back shortly afterwards, recorded it and photographed it.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre