Electronic Flora of South Australia Family Fact Sheet

Tribe BOSTRYCHIEAE Falkenberg 1901: 504

Phylum Rhodophyta – Family Rhodomelaceae

Thallus apices dorsiventrally developed, with polysiphonous indeterminate axes bearing polysiphonous and monosiphonous determinate laterals usually at regular intervals; trichoblasts absent; axes attached by clumped rhizoids. Branching mostly exogenous. Polysiphonous branches with 4–9 pericentral cells dividing transversely into 2–5 tiers; ecorticate or corticated.

Reproduction: Procarps formed on 2–6 or more successive polysiphonous segments, each segment with 1–4 procarps each with the fertile pericentral (supporting) cell, a lateral sterile group of 2–6 cells and a (3–) 4-celled carpogonial branch; carposporophyte with a branched gonimoblast bearing terminal carposporangia; cystocarps with a post fertilization pericarp of 6–14 longitudinal filaments, each cell cutting off 2 (–3) outer pericentral cells, usually corticated. Spermatangia forming an outer layer on polysiphonous determinate laterals.

Tetrasporangial stichidia on determinate laterals, each segment with 4–5 pericentral cells and whorled tetrasporangia, protected by cover cells.

The Bostrychieae includes the two genera Bostrychia Montagne and Stictosiphonia Hooker & Harvey. The features of the tribe have been emphasised most recently by Hommersand (1983) and Maggs & Hommersand (1993), who consider the tribe distinct from all the other tribes of the Rhodomelaceae, especially in its female reproduction. The tribe is distinguished in particular by complete absence of trichoblasts, pericentral cells dividing into 2–5 tiers, procarps borne on successive segments in ordinary branches and containing only one sterile group, pericarp formation only post-fertilization, and spermatangia formed on polysiphonous branchlets, not on trichoblasts.

References:

FALKENBERG, P. (1901). Die Rhodomelaceen des Golfes von Neapel und der angrenzenden Meeres-abschnitte. Fauna und Flora des Golfes von Neapel. Monogr. 26. (Friedländer: Berlin.)

MAGGS, C.A. & HOMMERSAND, M.H. (1993). Seaweeds of the British Isles. Vol. 1. Rhodophyta. Part 3A, Ceramiales. (HMSO: London.)

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 GENERA OF BOSTRYCHIEAE

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