Str. mannii is one of the species consolidated in Section Trachystigma following genetic and taxonomic analyses reported in the landmark study by Nishii et al (2015). The Section is unusual in that it has both unifoliate members like Str. mannii and conventionally stemmed plants like Str. nobilis. As a group within Subgenus Streptocarpella one might expect a stemmed habit, but the genetic analyses confirms that Section Trachystigma has both stemmed and unifoliate members.
The flowers are very attractive and could be a good horticultural subject. Its preferred habitat in the wet tropical biome imply it would require quite different cultural conditions than most Streptocarpus species and cultivars, which often prefer cool temperatures and tolerate some drought.
Str. mannii is not a large plant, leaf dimensions being on the order of 10 cm wide and just short of twice as long.
