The yellow flowers of the Turkish rocket appear in June–July and reach a metre in height, coating the road verges in a yellow sheen. It is hard not to be impressed by this brilliant yellow framework surrounding the hectic traffic around Brunnsviken. The Turkish rocket arrived in Uppland at the end of the 18th century, according to some sources with Russian seed. According to Linné it already existed in 1761 ‘on the dung heaps around Uppsala’. In the beginning of the 19th century it was fairly common in the Uppsala region. The species name,
orientalis, refers to its Eastern affiliations.
In some European countries such as Estonia and Germany, the species is considered to be invasive, that is, competitive with native species which thus are at risk of disappearing.