We here report the results from two parsimony analyses of all 15 recognized taxa in Hippophae (Elaeagnaceae), one based on chloroplast DNA (cpDNA), and one based on a combined data set of morphological characters and cpDNA. The genera Elaeagnus and Shepherdia were used as outgroup taxa. In general, the results are congruent with a previous RAPD study, and partly with some of the previous proposed classifications. Monophyly of Hippophae is strongly supported. The most widespread species, H. rhamnoides, is, in spite of low support, most likely monophyletic and distinguished by a single molecular synapomorphy. Due to weak internal support, we refrain from recognizing any sections within the genus. Three taxa, first published as nomina nuda but used by several authors, are here validated and/or described. These are Hippophae neurocarpa subsp. stellatopilosa, H. goniocarpa, and H. litangensis. The latter two were originally suggested to form one species with two subspecies, but they are clearly not monophyletic, a single lineage of evolution, but rather are sister to two different species in the analyses. Together with earlier information from isozymes (unpubl. data) and RAPDs, we believe they are results of two independent hybridisations and we describe them as species. In conjunction, a maternal mode of cpDNA inheritance is suggested.
Communicating Editor: Alan T. Whittemore