THE GENUS SYNARTHROPHYTON (CORALLINACEAE, RHODOPHYTA) IN SOUTHERN AUSTRALIA

The genus Synarthrophyton (Corallinaceae, Rhodophyta) is represented i n southern Australia by one species, S. patena (Hooker et Harvey in Ha rvey) Townsend. New data have shown that cell fusions vary in size and occur in both anticlinal and periclinal cell walls, and as a result c an no longer be used to delimit Synarthrophyton from other genera of M elobesioideae. Male conceptacle development is described for the first time. Spermatangia are overlain by protective cells during early stag es of development. Mature spermatangial branches may be either dendroi d or both dendroid and simple. Growth-form is more varied than hithert o thought and includes specimens previously identified as Lithothamnio n muelleri Lenormand ex Rosanoff. An updated description of Synarthrop hyton is presented and the relationships of Synarthrophyton to other g enera of the subfamily Melobesioideae are considered. New information is provided on host range, seasonal and geographic distribution in sou thern Australia.