Tetraplasandra, Munroidendron, and Reynoldsia sandwicensis are Hawaiian members of a complex of closely related genera in the Araliaceae that also includes Gastonia and the extra-Hawaiian species of Reynoldsia. Generic limits in the Tetraplasandra complex have been hazy and phylogenetic relationships within the genera have been uncertain. Systematic relationships within the Hawaiian group are presented here based on parsimony analysis of separate and combined data sets of nucleotide sequences from ITS 1 and 2 and 5S-NTS nuclear ribosomal DNA. Results of the analyses indicate that Tetraplasandra, Munroidendron, and Reynoldsia sandwicensis are monophyletic and Reynoldsia is paraphyletic. Both the ITS and 5S-NTS data sets support two major clades: a Munroidendron/Reynoldsia sandwicensis clade and a Tetraplasandra clade, but are discordant in relation to the monophyly of Tetraplasandra. Based on the 5S-NTS analysis, Tetraplasandra is paraphyletic, and the data support treating Tetraplasandra, Munroidendron, and Reynoldsia sandwicensis as a single genus. The ITS results support maintaining Tetraplasandra as a distinct genus from Reynoldsia and Munroidendron. The combined analyses are congruent with ITS results, resolving Tetraplasandra as a monophyletic genus. All of the analyses support combining Reynoldsia sandwicensis with Munroidendron and treating Reynoldsia sandwicensis separate from Reynoldsia species outside Hawaii. Tetraplasandra gymnocarpa is the only Araliaceae with a completely superior ovary, and in T. kavaiensis it is partially superior. Together, they form a well-supported clade within the Hawaiian complex, supporting the hypothesis that in Tetraplasandra superior ovaries evolved from an inferior-ovary ancestor. Research is underway to include a morphological data set; to be analyzed both independently and in combination with the molecular data sets.

Key words: 5S-NTS, Araliaceae, Gastonia, Hawaii, ITS