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Genus CHEILOSPORUM (Decaisne) Zanardini 1844: 1025

Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Corallinoideae – Tribe Janieae

Thallus tufted, with several to numerous erect, subdichotomous fronds, complanately branched, with compressed intergenicula each bearing two compressed lobes; holdfasts crustose, developing basal stolons with new erect fronds, epilithic or epiphytic. Structure. Intergenicula with 5–10 (–12) tiers of medullary cells with lateral cell-fusions but without lateral pit-connections, extending to 20 tiers in the lobes. Genicula of single tiers of elongate cells, with darkly staining walls. Cortex present on intergenicula, of splaying filaments of elongate cells, outer cells with short epithallial cells.

Reproduction: Conceptacles single (–3), embedded within the fertile lobes, pore adaxial or apical. Gametangial thalli dioecious. Carpogonial filaments 2-celled, arising on the floor of female conceptacles, carposporangia terminal in 2–4 celled filaments on the margins of the relatively thick fusion cells. Male conceptacles elongate, chamber narrow, with spermatangia arising on the floor and sides.

Tetrasporangial conceptacles on separate thalli, with tetrasporangia arising from the chamber floor.

Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Lectotype species: C. sagittatum (Lamouroux) Areschoug 1852: 545. (Schmitz 1889: 455.)

Taxonomic notes: Cheilosporum is a distinctive genus, with each intergeniculum bearing two upwardly-projecting lobes, with the conceptacles formed within the lobes and opening on their adaxial edges. It contains some 5 species (Srimanobhas et al. 1990), most confined to tropical-subtropical waters but one (C. sagittatum) present in temperate seas.


ARESCHOUG, J.E. (1852). Ordo XII. Corallineae. In J.G. Agardh, "Species, Genera et Ordines Algarum". Vol. 2, Part 2, pp. 506–576. (Gleerup: Lund.)

SCHMITZ, F. (1889). Systematische Ubersicht der bisher bekannten Gattungen der Florideen. Flora, Jena 72, 435–456, Plate 21.

SRIMANOBHAS, V., BABA, M., AKIOKA, H., MASAKI, T. & JOHANSEN, H.W. (1990). Cheilosporum (Corallinales, Rhodophyta) in Japan: a morphotaxonomic study. Phycologia 29, 103–113.

ZANARDINI, G. (1844). Sulle Corallinee. Enciclopedia italiana o dizionario della conversazione, Venezia, Tasso 6, 1013–1036.

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

Author: H.B.S. Womersley & H.W. Johansen

Publication: Womersley, H.B.S. (28 June, 1996)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIB. Gracilarialse, Rhodymeniales, Corallinales and Bonnemaisoniales
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIB 1996, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

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