Hypericum maculatum Imperforate St John's-wort

A square-stemmed St John's-wort with short rhizomes which grows in rough grassland, roadside verges, waste places, along railways and woodland edges. It has a patchy distribution in Britain where it is fairly widespread in Wales but absent from much of central and eastern England and often quite local in those parts of the country where it is found. In Wales it is represented exclusively by subspecies obtusiusculum. The leaves lack the translucent dots that are abundant on the leaves of Perforate St John's-wort (Hypericum perforatum) and the stems are obviously square with four raised lines along their edges, but not winged like those of Square-stemmed St John's-wort (Hypericum tetrpterum). It hybridises with Perforate St John's-wort (both parents are 2n=32) to form a fertile hybrid, Desetangs St John's-wort (Hypericum x desetangsii) with which it is easily confused (see description of Hypericum x desetangsii). It has been recorded widely in the South Wales Coalfield in West Glamorgan but it is uncommon in Gower. Some (perhaps most) records are probably misidentifications of Desentang's St John's-wort. Like Perforate St John's-wort, it conatins a number of interesting phytochemicals like polycyclic anthraquinone,hypericin, which has been the subject of lots of research in view of its alleged antidepressant properties.