Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Acrotylaceae
Thallus erect, with the main axis bearing irregularly long lateral, terete, branches, covered irregularly with short, ovoid to clavate ramuli, single or in chains of 2–3; holdfast discoid. Structure multiaxial, with a laxly filamentous reticulate medulla (dense below in main branches) and a pseudoparenchymatous cortex 2–4 cells thick, increasing below.
Reproduction: Sexual thalli monocarpogonial, probably procarpic. Carpogonial branches 3-celled, borne on inner cortical cells near apices of ramuli, inwardly directed with reflexed trichogynes. Supporting cell becoming the auxiliary cell and producing several gonimoblast initials thallus inwardly, within a broad filamentous enveloping tissue developed from adjacent vegetative cells. Gonimoblast filaments entering the enveloping tissue as the auxiliary cell disintegrates, producing centripetal tufts of filaments within the expanding cavity, bearing single terminal carposporangia. Cystocarps embedded in the ramuli, with filamentous enveloping tissue and a cortical ostiole. Spermatangia unknown.
Tetrasporangia scattered in the outer cortex, laterally pit-connected, ovoid, zonately divided.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type (and only) species: C. ovatum (Lamouroux) Kraft & Min-Their 1983: 172.
Taxonomic notes: Claviclonium is distinctive in form but appears to agree well structurally and reproductively with the Acrotylaceae.
References: The Marine Benthic Flora of Southern Australia Part IIIA
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
State Herbarium of South Australia