Halydictyon Zanardini, 1843

Holotype species: Halydictyon mirabile Zanardini

Original publication and holotype designation: Zanardini, G. (1843). Saggio di classificazione naturale delle Ficee del Dottore Giovanni Zanardini aggiunti nuovi studii sopra l'androsace degli antichi con tavola miniata ed enumerazione di tutte le specie scoperte e raccolte dall'autore in Dalmazia. pp. [1]-64, 2 folded tables, 1 col. pl. Venezia [Venice]: Dallo Stabilimento tipographico enciclopedico di Girolamo Tasso.

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Precise date of publication: March 1843

Description: Thallus formed as a three-dimensional, irregularly polygonal network without a distinct main axis. Networks erect from decumbent axes, sympodially developed monosiphonous axes irregularly branched. Indeterminate axes terete or slightly compressed and alternately and distichously producing determinate pseudolateral branch systems from every other polysiphonous segment. Pseudolaterals pigmented, polysiphonous basally and centrally, monosiphonous elsewhere, at first subdichotomously, then alternately and distichously branched, ultimately developing as secondary sympodia, with maturity and growth of connective cells becoming interlinked, spirally disposed networks surrounding the axes. Network margins beset with short spur-like branches. Networks in total making the axes appear angular, fan-shaped or terete, these often becoming deciduous below, after which adventitious indeterminate branches can develop. Axial cells of indeterminate axes surrounded by 4 periaxials which are quickly enclosed by descending rhizoidal filaments, collectively forming a thick cortex. Monoecious or dioecious, spermatangia formed in compressed stichidia on short determinate branches in upper portions of networks, the stichidia bearing a marginal band of larger vegetative cells. Basal cell of male branches remaining as undivided pedicels. Procarps formed on short determinate branches off networks, developing from suprabasal polysiphonous segments with 4 periaxial cells. Procarps each consisting of a 2-celled carpogonial branch surrounded by a curved bed of the 4 periaxial cells (the type is shown not to produce a trichogyne: Coppejans 1975). Cystocarps projecting from the network, urceolate with pronounced beaks. Tetrahedral sporangia produced in opposite pairs, forming simple, compressed lanceolate stichidia on monosiphonous pedicels. Tetrasporangia completely enclosed by cover cells at maturity.

Information contributed by: C.W. Schneider. The most recent alteration to this page was made on 2023-12-11 by M.D. Guiry.

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

Gender: This genus name is currently treated as neuter.

Most recent taxonomic treatment adopted: Schneider, C.W. & Wynne, M.J. (2007). A synoptic review of the classification of red algal genera a half a century after Kylin's "Die Gattungen der Rhodophyceen". Botanica Marina 50: 197-249.

Comments: Halydictyon mirabile is known only from the North Atlantic, the Caribbean, Bermuda, the Mediterranean and Macaronesia. The other four species, two remaining unnamed, are from the Indian Ocean: eastern South Africa, Mauritius and Western Australia. The orthography of the genus name was discussed by Silva et al. (1996) who use the original Zanardini (1843) spelling rather than that commonly used and first introduced by Montagne (1847).

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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=33929

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 11 December 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 19 March 2024

 
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