Phaeocolax Hollenberg, 1967
Holotype species: Phaeocolax kajimurae Hollenberg
Original publication and holotype designation: Hollenberg, G.J. (1967). New genera in the Rhodomelaceae from the Central Pacific. Bulletin of the Southern California Academy of Sciences 66: 201-221, 15 figs.
Request PDFDescription: Minute hemiparasites, with a discoid base, replacing the outer layer of the host but without penetrating rhizoidal processes; erect primary axis bearing several lateral branches radially arranged; pericentral cells mostly about 8, surrounded by a cortex of 2-3 layers of cells somewhat smaller than the pericentral cells, which develop pit-connections with adjacent cortical cells; branches bearing numerous short, radially arranged, mostly simple, conical branchlets; branchlets bearing numerous long, unbranched, colorless trichoblasts; tetrasporangia in whorls of 5-8 per segment in the branchlets; cystocarps globular-ovate, with a small ostiole on the low conical apex; spermatangial stichidia very numerous, arising from trichoblast primordia.
Thalli epiphytic on Lobophora; one to several upright axes, up to 6 mm tall, produced from an endophytic discoid base anchored in host tissue. Discoid base developing subepidermally in host, upright monosiphonous filaments breaking through host surface. Upright branches monopodial, becoming polysiphonous with 6 corticated pericentrals with spirally arranged unbranched trichoblasts or polysiphonous branches replacing them. Cortication up to 2 layers thick covering all but branch apices. Reproductive cells formed on erect branches. Carpogonial branches produced on fertile trichoblasts with 5 proximal pericentrals; procarp consisting of a supporting cell with a laterally borne 4-celled carpogonial branch and a terminal sterile cell. Cystocarp ostiolate and spheroidal. Male upright branches somewhat shorter than those of female plants or tetrasporophytes; male capitula replace some trichoblasts, capitula ovaloid and with a sterile tip. Tetrasporangia borne in whorls on branchlets, a sporangium produced by each pericentral cell.
Information contributed by: Original description and R.E. Norris. The most recent alteration to this page was made on 2022-12-20 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 masculine.
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: Known only on the host, Lobophora variegata, on the southern shore of Oahu, Hawaiian Islands, Pacific Ocean. At first believed to be a partial parasite on the brown algal host, Phaeocolax was shown not to have pit connections nor any other type of direct connection with its host (Apt 1984); Apt also demonstrated that Phaeocolax can be grown in culture without the host for over a year.
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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=42875
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 20 December 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 26 April 2024
