This West African tropical species was long separated from Streptocarpus, which it clearly resembles, on the basis of the straight seed pod (clearly illustrated in the print). A twisted seed pod was one of the principal characteristics of Streptocarpus, and is embedded in the name (Strepto = twisted, carpus = fruit). However, recent genetic studies have confirmed that this genus, along with several others, are properly understood as belonging in Streptocarpus, untwisted fruits notwithstanding.
Image courtesy of www.plantillustrations.com.