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Electronic Flora of South Australia Genus Fact Sheet

Genus TAONIA J. Agardh 1848: 101

Phylum Phaeophyta – Order Dictyotales – Family Dictyotaceae – Tribe Zonarieae

Thallus complanate, flabellate and lacerate with elongate and cuneate segments, usually 5–20 cm long with segments 0.5–3 cm broad, often tapering to the apices. Growth by a marginal row of many apical cells in a convex apex. Structure 2–4 (–6) cells thick, with the outer cells the same size as inner cells, cells regularly arranged in transverse section of young parts, irregular in older parts. Hairs phaeophycean, in concentric zones.

Reproduction: Sporangia scattered, with or without a stalk cell, partly or entirely lying above the thallus surface, producing four spores. Sexual reproduction rare, with antheridial and doubtfully oogonial sori.

Life history probably diplohaplontic or direct from the sporophyte.

Type species: T. atomaria (Woodward) J. Agardh.

Taxonomic notes: Taonia includes three species, characterised by the broad margin of apical cells, concentric zones of hairs, cells of similar size in transverse section, and sporangia external to the blade. The reproduction and possible life history of T. lennebackeriae Farlow ex J. Agardh from southern California, and T. atomaria, have been discussed by Mathieson (1966).


AGARDH, J.G. (1848). Species, Genera et Ordines Algarum. Vol. 1. (Gleerup: Lund.)

MATHIESON, A.C. (1966). Morphological studies on the marine brown alga Taonia lennebackerae Farlow ex J. Agardh. I. Sporophytes, abnormal gametophytes and vegetative reproduction. Nova Hedwigia 12, 65–79, Plates 11–14.

The Marine Benthic Flora of Southern Australia Part II complete list of references.

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
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