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Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Rhodymeniales
Thallus erect or decumbent, much branched radially or distichously, branches terete to compressed, hollow and usually irregularly segmented by multilayered partitions or plugs without distinct longitudinal filaments in the medulla; monostromatic septa absent. Structure multiaxial, with a group of apical cells producing a cortex 3–6 cells thick and a medulla consisting of a network of filaments bearing secretory cells.
Reproduction: Gametangial thalli dioecious; procarpic. Carpogonial branches 3-celled, borne on inner cortical cells together with one or two 2-celled auxiliary cell branches. Carposporophytes with or without basal nutritive tissue, with a basal fusion cell and most gonimoblast cells forming carposporangia, surrounded by stellate cells of the inner pericarp. Cystocarps protuberant, sessile, pericarp ostiolate. Spermatangia in surface sori, cut off from initials on the outer cortex.
Tetrasporangia in small, depressed, sori, terminal on cortical cells, tetrahedrally divided.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Taxonomic notes: A family of five genera, now usually separated from the Champiaceae by multilayered partitions separating the segments, irregular medullary filaments rather than discrete longitudinal ones, carposporophytes with most cells forming carposporangia, and tetrasporangia in small, depressed sori, cut off (rather than transformed) from outer cortical cells.
References:
AGARDH, J.G. (1876). Species Genera et Ordines Algarum. Vol. 3, Part 1 — Epicrisis systematis Floridearum, pp. i-vii, 1–724. (Weigel: Leipzig.)
The Marine Benthic Flora of Southern Australia Part IIIB complete list of references.
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.
KEY TO GENERA OF LOMENTARIACEAE
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1. Cystocarps protuberant, with a well-developed pericarp | LOMENTARIA |
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1. Cystocarps immersed, surrounded by a filamentous involucre derived from inner cortical cells | SEMNOCARPA |
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Email Contact: State Herbarium of South Australia |
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