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Order Ceramiales

Family Ceramiaceae

Compsothamnionella sciadophila Stegenga 1990: 94-98, figs. 1, 2

Plants up to a few cm tall, with in principle one erect axis, but basal-most segments often with a number of indeterminate laterals. Holdfast consisting of many multicellular rhizoids. ‘Erect’ axes spreading more or less parallel to the substrate. Main axis up to 200 µm in diameter, tapering to ca. 15 µm in the apical cells, branching alternately, strictly in one plane; ramification to the fifth order, in principle from every cell. Cells throughout the plant about as long as broad. The older segments of the main axis develop an incomplete cortication as a rhizoidal branch from the basal cell of a lateral connects with the (higher-order) lateral from two segments below.

Tetrasporangia develop on one side (the upper side) of the erect axes, on the final ramifications; they measure up to 45 µm in diameter, being perfectly globular and tetrahedrally divided. Occasionally a (slightly larger) octosporangium is found. Male stands conical, with a 5-10-celled central axis, on the terminal or subterminal-order branchlets. Female stand developing subterminally on third and fourth order branchlets, the procarp situated on the second to fifth cell below the apex. Carposporophyte several subglobose gonimolobes, surrounded by a number of branched involucral filaments originating from the cells below the fertile axial cell.

Collections, ecology and regional distribution

Recorded from False Bay to the East London area (17-41). An inconspicuous, though not uncommon member of (shaded) algal communities in lower intertidal rock pools. Grows as an epiphyte on a variety of algae, but apparently can occur also on lifeless substrata.

World distribution: South African endemic.

Type locality: Three Sisters, Eastern Cape, South Africa (Stegenga 1990).

 


Compsothamnionella sciadophila 1.Thallus apex. 2 Tetrasporangia. Reproduced from Stegenga et al. (1997).


Compsothamnionella sciadophila , thallus with tetrasporangia. Stained slide specimen, Walker Point (near Goukamma).


Compsothamnionella sciadophila , tetrasporangia. Stained slide specimen, Walker Point (near Goukamma).


Compsothamnionella sciadophila , older axes with “cortical filaments” connecting laterals. Stained slide specimen, Walker Point (near Goukamma).

 

References Compsothamnionella sciadophila

Stegenga, H. (1990. The genus Compsothamniella Itono (Ceramiaceae, Rhodophyta) on the South African coast. Acta Botanica Neerlandica 39: 93-99, 2 figs.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 18 December 2018.