C. alexandri from the biflorus group is easily to identify because at present there are known only two species with a white throat. The other is C. weldenii, but its leaves have 1 or 2 prominent ribs in the lateral channels. In the garden C. alexandri is an easy grower and according to E. A. Bowles, they “make splendid garden plants, flowering rather late”. My plants comes from Mt. Falakro in Makedonia (Greece).