Taxonomic notes on marine algae from Malaysia. V. Five species of Rhodymeniales (Rhodophyceae)

Five species of the red algal order Rhodymeniales are reported from Malaysi a for the first time and their characteristic features are described: Chama ebotrys boergesenii (Weber-van Bosse) Huisman (Rhodymeniaceae), Coelarthrum sp. (Rhodymeniaceae), two species of Champia (Champiaceae), C. compressa H arvey and C. vieillardii Kutzing, and Lomentaria monochlamydea (J. Agardh) Kylin (Lomentariaceae). The alga with vegetative features similar to the Ch amaebotrys/Coelarthrum group is new to science and is characterised by the presence of a conspicuously developed, solid, cartilaginous stipe. This alg a seems to be more closely related to Coelarthrum on the basis of its uprig ht habit rather than Chamaebotrys, which has decumbent or prostrate thalli. The production of slender branches in Champia vieillardii is an additional critical feature that distinguishes it from a closely related species, C. compressa.