After giving a detailed description of the main characters of C. arabica L. var. anomala K. M. C, the authors present the results of its genetic analysis. It was found that it is recessive to the "normal" C. arabica, one single pair of genes - an an - being responsible for the appearance of all its main differentiating characteristics. The influence of this pair of genes is rather remarkable, affecting nearly all of the plant characters, as habit of growth, type of branching, shape and size of leaves and the morphology of flowers, fruits and seeds. The F1 hybrids show almost complete dominance of the normal type, with the exception of the occasional occurrence of a few leaf pairs, the apex of which is slightly deformed. The appearance of this abnormality in F1 is thought to be due to special environmental conditions which permit the manifestation of the single an allele, or a conseguence of some sort of abnormal cytological behavior.