This is a really common plant, flowering at this time of year through until early summer. I took this picture in the area outside the front of my flat. It usually wont grow larger than 90cm and it likes damp shady areas near buildings. Anyone who lives in London will have seen this plant, whether they recognize it or not. Until today, I didn’t know what it was but it is really interesting. It was bought here in the middle ages , predominantly to be used as a dye which is a strong red and is extracted from the roots. Both flower and leaf are edible but always be 100 percent sure of identification before you consume anything. The leaves stay green throughout the year, hence the first part of the plants common name and the second part is related to henna denoting the dying properties.