New Records and Notes on Hawaiian Marine Benthic Chlorophyta, including Pseudochlorodesmis abbreviata (Gilbert), n. comb. (Udoteaceae) and Cladophora luxurians (Gilbert), n. comb. (Cladophoraceae)l

Morphology, taxonomy, and nomenclature of three species of Hawaiian green algae (Chlorophyta) are examined. Udotea? abbreviata Gilbert is shown to be incorrectly placed in that genus and more appropriately allied to Pseudochlorodesmis. The complex nomenclatural relationships of Cladophora tildeniae Brand in Tilden, Cladophora tildeniae Brand, and Cladophora hawaiiana Tilden are described, with the latter deemed the appropriate name and Microdietyon japonicum var. laxum Gilbert regarded as a synonym. An examination of Cladophoropsis luxurians Gilbert has shown it to have delayed formation of transverse walls at the bases of lateral branches, a feature not consistent with inclusion in Cladophoropsis but rather with Cladophora. The new combinations Pseudochlorodesmis abbreviata (Gilbert) Abbott & Huisman and Cladophora luxurians (Gilbert) Abbott & Huisman are made, and nine species of marine benthic Chlorophyta are newly recorded for the Hawaiian Islands. THE MARINE BENTHIC algal flora of the Hawaiian Islands has, historically and recently, received a great deal of attention, both from indigenous Hawaiians as a source of food and from phycologists as constituting a particularly rich biodiversity and as a source of many interesting and novel taxa. A recent outcome of this attention was the publication of Marine red algae of the Hawaiian Islands (Abbott 1999), the first major algal flora for the central Pacific and the first of a series that eventually also will include the brown and green seaweeds. During preparatory research for the Chlorophyta volume we encountered three species with a confused nomenclatural and taxonomic past, as well as documented nine new records for the Hawaiian Islands, all of which we report here. I Research supported by the David and Lucile Packard Foundation. Manuscript accepted 17 October 2002. 2 Department of Botany, University of Hawai'i at Manoa, 3190 Maile Way, Honolulu, Hawai'i 96822. Pacific Science (2003), vol. 57, no. 3:275-285 © 2003 by University of Hawai'i Press All rights reserved MATERIALS AND METHODS Plants were preserved either in formalin! seawater or as dried herbarium specimens and on microscope slides. Materials for slide preparations were stained with aniline blue and mounted in water for photography, and then infused with corn syrup (Karo, CPC International) solution to make permanent mounts. Pyrenoids were observed by staining with Lugol's solution. Specimens were examined with a microscope (Olympus BX3) and photographed using a digital camera (Olympus D11). Herbarium abbreviations follow Holmgren et al. (1990) with the exception of lA, which refers to the 1. Abbott collection housed at the Department of Botany, University of Hawai'i at Manoa.