Staurosira stevensonii sp. nov. (Bacillariophyta), a new taxon from Florida, USA

A new species, Staurosira stevensonii, is described from Florida. USA. This new taxon was first found during examination of depositional material from Lake Okeechobee and lately in recent collections from a number of additional localities. Light and scanning electron microscopy indicate a clear relationship with species in the genus Staurosira. Some of the characteristic features of the new taxon include an elegantly cruciform valve outline, slightly capitate valve poles, a constant number of 6 areolae in 1 μm, highly reduced apical pore fields, and open ends between neighbouring cells caused by the reduced size of spines at the valve apices. A higher relative abundance was recorded in bogs and marshes, which indicates the preference of this taxon for acidic environments.