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Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Family Rhodomelaceae – Tribe Amansieae
Thallus erect, more-or-less pinnately and complanately branched, branches flat, linear to serrate with determinate pinnules, with horizontal tiers of elongate cells in surface view, wings ecorticate, midrib slight to prominent; apices circinnate. Structure. Apical cells in circinnate apices, axial cells cutting off 5 pericentral cells, 2 lateral on each side and one ventral, with the dorsal-lateral pericentral cells and occasionally the ventral cell each cutting off a pseudopericentral cell; the lateral pericentral cells divide rapidly to produce the distromatic wings, the elongate cells in surface view lying in horizontally aligned tiers and slightly overlapping at their ends.
Reproduction: Gametophytes dioecious. Reproductive organs borne on short, spinous, marginal shoots or the spinous pinnules. Procarps borne on reduced or normal trichoblasts which are soon polysiphonous and pericarpic. Carposporophytes with a basal fusion cell and much-branched gonimoblast with clavate terminal carposporangia. Cystocarps globose to ovoid, stalked; pericarp ostiolate, corticate and 3–6 cells thick. Spermatangial organs clustered on the determinate laterals, ovoid, with a sterile basal cell.
Tetrasporangial stichidia on the determinate laterals, elongate, curved to circinnate, compressed, with 2 rows of paired tetrasporangia.
Type species: A. multifida Lamouroux 1809a: 332, pl. 6 figs C-E.
Taxonomic notes: Norris (1988a, p. 210) claimed that no pseudopericentral cells were present in the type species, A. multifida, and on this feature he segregated several species as a new genus
Melanamansia. However, study of A. multifida from Rocas, Santo Domingo (Almodovar & Rivas, 27 July 1977, CIBIMA 7634; AD, A49316) shows that pseudopericentral cells do occur (Fig. 170A). Other supposed differences are insignificant. Hence Melanamansia Norris should become a synonym of Amansia.
Amansia is characterised by its habit, ecorticate wings of 2 layers of elongate tiered cells, and axes with 5 pericentral cells plus usually 2 pseudopericentral cells. Besides the 3 southern Australian species described below, several other species occur on northern coasts of Australia.
References:
LAMOUROUX, J.V.F. (1809a). Observations sur la physiologic des algues marines, et description de cinq nouveaux genres de cette famille. Nouv. Bull. Sci. Soc. Philom. Paris 1, 330–333, Plate 6.
LAMOUROUX, J.V.F. (1809b). M6moire sur trois nouveaux genres de la famille des Algues marines. J. de Bot. 2, 129–135.
NORRIS, R.E. (1988a). Structure and reproduction of Amansia and Melanamansia gen. nov. (Rhodophyta, Rhodomelaceae) on the southeastern African coast. J. Phycol. 24, 209–223.
The Marine Benthic Flora of Southern Australia Part IIID complete list of references.
Publication:
Womersley, H.B.S. (24 February, 2003)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIID. Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIID 2003, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
KEY TO SPECIES OF AMANSIA
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1. Branches mostly | A. mamiliaris |
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1. Branches mostly | 2 |
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2. Branches linear with entire margins apart from short reproductive laterals | A. pinnatifida |
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2. Branches bipinnate, with short, marginal, alternate, determinate, spinous pinnules | A. serrata |
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Email Contact: State Herbarium of South Australia |
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