The marine algae of British Columbia, northern Washington, and southeast Alaska: division Rhodophyta (red algae), class Rhodophyceae, order Gelidiales

Abstract

The red algal order Gelidiales is represented in the benthic marine algal flora of British Columbia, northern Washington, and southeast Alaska by two genera, Gelidium Lamouroux and Pterocladia J. Agardh. Three species of Gelidium are present, G. coulteri Harvey, G. purpurascens Gardner, and G. vagum Okamura, and one species of Pterocladia, P. caloglossoides (Howe) Dawson. For each species we provide a description of its habit and life history, vegetative and reproductive morphology, and habitat and seasonality. Distributions and representative specimens examined are given. Keys are provided to genera and species where appropriate. Habits, and salient vegetative and reproductive features useful in identifying each species, are illustrated. Gelidium vagum is reported for the first time in the northeast Pacific and appears to have been introduced to the flora from Japan in recent historical time. Its distribution is limited to two islands in the Strait of Georgia. Gelidium purpurascens and Pterocladia caloglossoides are distributed throughout British Columbia and northern Washington, and their ranges are extended north to southeast Alaska. Earlier reports of G. amansii (Lamouroux) Lamouroux, G. crinale (Turner) Lamouroux, G. pusillum (Stackhouse) Le Jolis, G. robustum (Gardner) Hollenberg et Abbott, and G. sinicola Gardner from British Columbia and northern Washington are shown to have been based upon misidentifications of other taxa, and these species are excluded from the flora.