The taxonomic significance of cyanogenesis in Lotononis and related genera

Reports on cyanogenesis in the genus Lotononis are limited to five species. In a survey using the Feigl-Anger spot test, a further 52 species of Lotononis and four species of the closely related Buchenroedera were found to by cyanogenic. Species of other genera in the tribe Crotalarieae all gave a negative result. Cyanogenesis appears to be a character of considerable chemotaxonomic value in Lotononis, with some groups of species cyanogenic and others acyanogenic. These groups usually follow the traditional sectional classification. Lack of morphological uniformity within a section is also reflected in the cyanogenesis data and this may provide useful additional evidence to improve the existing classification. The data support the view that the genera Lotononis and Buchenroedera are congeneric.