The present study is but one of several treatments of the genus. However, all previous treatments have either concentrated on the genus in part, or have been part of a larger and more extensive work of either taxonomic or phytogeographic nature. Celmisia has been regarded by many taxonomists as being “difficult” to classify both at the species level and at the generic. This is still true to some extent, though modern techniques of study are rapidly solving many of the problems found in genera of similar complexity. Although computer techniques have not been used in this treatment they will probably prove useful, particularly at the subgeneric level. However, traditional techniques such as comparative morphology are still powerful tools in the hands of the taxonomist and much of this study is concerned with those methods.