Amphiplexia J.Agardh, 1892

Holotype species: Amphiplexia hymenocladioides J.Agardh

Original publication and holotype designation: Agardh, J.G. (1892). Analecta algologica. Lunds Universitets ÅrsSkrift, Andra Afdelningen, Kongl. Fysiografiska Sällskapets i Lund Handlingar 28(6): 1-182, 3 pls.

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Description: Plants reach 16 cm in length and grow singly or in clusters from a crustose base. They are irregularly branched and tubular throughout, or composed of tubular branches on a cartilaginous main axis. Tubular branches are mostly filled with mucilage in which isolated medullary strands are scattered. The cortex consists of an inner layer of large subisodiametric cells at an abrupt transition from the medulla, and 1-2 outer cortical layers that form surface rosettes around the inner cortical cells. Supporting cells are monocarpogonial, bear a 3-celled carpogonial branch lacking sterile laterals, and appear to be diploidized by a direct tubular outgrowth from the fertilized carpogonium. Gonimoblasts develop outwardly across a basal nutritive tissue on the floor of a prominently protuberant, ostiolate pericarp. Carposporangia form in chains of 2-3 from filaments lining the pericarp wall or erupting from the floor of the cystocarp cavity. Tetrasporangia are formed in an intercalary position within the cortex over wide areas of the plant (Kraft, 1977).

Information contributed by: G. Kraft. The most recent alteration to this page was made on 2021-06-18 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Kraft, G.T. & Saunders, G.W. (2021). The Acrotylaceae (Gigartinales) revisited: molecular data indicate family-level differences in one of the most enigmatic red-algal families. Australian Systematic Botany 34(3): 305-326, 13 figs, 1 table.

Comments: Distribution: Plants occur in open light on rock, seagrass stems and jetty pilings from 3-30 m depths; the type species is recorded from the Perth region (Western Australia) along the southern coast to Port Phillip Heads (Victoria). The second species, A. racemosa (J. Agardh) Kraft, is of much more restricted distribution and occurrence from the Perth region to Elliston (South Australia) .

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=34971

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 18 June 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 April 2024