XVI International Botanical Congess

Examination of diatom collections from wet caves, seeps on cliffs, and rock walls moistened by waterfall spray from the islands of Kaua'i, O'ahu, Maui, and Hawai'i reveals much variation in species composition. A few diatom taxa are common to several but not all of these habitats, e.g. Caloneis hyalina, Diadesmis confervacea, D. contenta fo. biceps, Nitzschia amphibia, Rhopalodia gibba, R. gibberula var. vanheurckii. These associations are dominated by several taxa, including Achnanthidium minutissimum, Caloneis leptosoma, D. confervacea, Nitzschia hantzschiana, Orthoseira dendroteres, and an unidentified filamentous araphid. Species composition indicates affinities to both soil and stream floras. Navicula thurstonensis also occurs in streams.