Where the calyx and corolla are not clearly differentiated, use the corolla characters for the perianth.
Although calyx colour is a good and useful feature it should be used with discretion in this version of the Key because we have experienced difficulty in compiling information on this character. Collectors seldom bother to record calyx colour, even if they record corolla colours in great detail. Calyx colours ascertained from dried or pickled specimens may or may not correspond with reality. Therefore, it is recommended that calyx colours be used at the very end of the identification process so that the operator can see what effect it has on the number of possibilities and if necessary check both groups of species.