PHORADENDRON OLAE KUIJT, A NEW SPECIES FROM MEXICO PIVOTAL IN THE TAXONOMY OF THE GENUS, WITH COMMENTS ON P-CALIFORNICUM NUTT

Materials are presented to the effect that Phoradendron californicum N utt., the nomenclatural type of the genus Phoradendron (Viscaceae), is related to southern, cataphyllous species, not to northern, acataphyl lous ones. The evidence consists of the frequent occurrence of basal c ataphylls in the species, variation in basal phyllotaxy, and a basical ly biseriate arrangement of flowers on fertile internodes. The suggest ion of this southern, cataphyllous affinity is supported by the recent discovery of a strictly cataphyllous Mexican species, P, olae Kuijt, which shows median basal phyllotaxy and is in many features extremely similar to P. californicum. The nomenclatural consequences of this dis covery would lead to subgen. Boreales (Trel.) Engler (and probably sub gen. Aequatoriales (Trel.) Engler) being synonymized under subgen. Pho radendron, characterized by basal cataphylls (though not in all specie s). However, no generic subdivision of any sort is supported at this t ime.