Electronic Flora of South Australia Genus Fact Sheet
Phylum Phaeophyta – Order Scytosiphonales – Family Scytosiphonaceae
Thallus irregularly globular to convolute or elongate-ovoid, often bullate, usually not more than twice (-3 times) as high as broad, hollow, with a thin, crisp thallus wall (membrane) when living, attached by a small, crustose to irregularly spreading, usually vague, base; epilithic or epiphytic. Growth diffuse. Structure of inner, large, clear medullary cells, 2–6 cells thick, and 1–3 small cortical cells with the outer cells containing a single phaeoplast and pyrenoid; physodes numerous. Phaeophycean hairs in scattered groups, becoming sunken within pits.
Reproduction: Plurilocular organs in sori, discrete or spreading irregularly over the surface, accompanied by elongate, unicellular or 1–3 celled paraphyses, and in some species covered by an overall cuticular membrane. Zooids usually acting as zoospores reproducing the macrothalli, but at certain periods fusing sexually as iso- or anisogametes, or developing parthenogenetically.
Life history diplohaplontic or direct from haploid macrothalli, with filamentous or pulvinate microthalli (Clayton 1979).
Type species: C. sinuosa (Mertens ex Roth) Derbés & Solier
Taxonomic notes: A genus of 7 or 8 species (Parsons 1982, p. 289), the type and C. peregrina (Sauvageau) Hamel being widely distributed, and the other species mainly in the Pacific region. Clayton (1979) reviews knowledge of the life history and reproduction of the genus.
Determination of the species of Colpomenia requires good, fertile, material, preferably examined fresh or liquid preserved.
CLAYTON, M.N. (1979). The life history and sexual reproduction of Colpomenia peregrina (Scytosiphonaceae, Phaeophyta) in Australia. Br. phycol. J. 14, 1–10.
DERBÉS, A. & SOLIER, A.J.J. (1851). Algues. In Castagne, J.L.M., Supplément au Catalogue des plantes qui croissent naturellement aux environs de Marseille. pp. 93–121. (Nicot & Pardigon: Aix.)
PARSONS, M.J. (1982). Colpomenia (Endlicher) Derbés & Solier (Phaeophyta) in New Zealand. N.Z. J. Bot. 20, 289–301.
The Marine Benthic Flora of Southern Australia Part II complete list of references.
Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
KEY TO SPECIES OF COLPOMENIA
1. Sori punctate, usually surrounding a hair group, with an overall cuticular membrane
1. Sori extensive or irregular in shape, with scattered hair groups, without an overall cuticular membrane
2. Sori extensive over thallus surface; paraphyses single-celled, clavate
2. Sori narrow, irregular or reticulate; paraphyses
State Herbarium of South Australia