Perforate St John's Wort (Hypericum perforatum) wildflower

Ref: perforate

In some circumstances this species is able to reach 1.5 m in height and is in flower during July and August. St John’s Wort was originally called St Johannes Gyrs (grass) but re-named in 1551.The tops of the young plants, when mordanted with alum, give a yellowish-red dye once used in Scottish tartans.