Campylosiphon congestus (H.C. Wright) Merckx ex Maas

Firstly described as Gymnosiphon congestus by Wright (1898), transferred to Burmannia congesta by Jonker (1938), as such accepted by Zhang (2001) and Govaerts et al. (2007), but included in Campylosiphon due to morphological (no wings at the floral tube, tuberous subterraneous organ) as well as molecular data by Merckx (2006, 2008) and Merckx et al. (2008). This is accepted and formalized by Maas and Maas-van de Kamer (2010).
The close relative Burmannia densiflora coined by Schlechter (1906) shares the above mentioned features with C. congestus. It has been accepted by Jonker (1938) as a separate species, but Govaerts et al. (2007) as well as Maas and Maas-van de Kamer (2010) synonymize it with Burmannia congesta/Campylosiphon congestus, respectively, also due to the molecular data of Merckx (2006, 2008). Campylosiphon congestus occurs in Cameroon, Nigeria, Kongo, Angola.