Lemanea Bory, 1808, nom. cons.
Holotype species: Lemanea corallina Bory
Currently accepted name for the type species: Lemanea fluviatilis (Linnaeus) C.Agardh
Original publication and holotype designation: Bory de Saint-Vincent, [J.B.G.M.] (1808). Mémoire sur le genre Lemanea de la famille des Conferves. Annales du Muséum d'Histoire Naturelle 12: 177-190, pls 21, 22.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Athanasiadis, A. (2016). Phycologia Europaea Rhodophyta Vol. I. pp. [i]-xxxxviii, 1-762. Thessaloniki: Published and distributed by the author.
Description: Tufts of cartilaginous, tubular, pseudoparenchymatous gametophytic thalli, lacking cortical filaments around central, uniseriate axis. T- or L-shaped ray cells closely applied to outer cortex. One-40 cm long and 0.2-2.0 mm diam. Blue-green to olive when young, becoming rusty-brown to black at maturity. Species characterized by presence of branching, diameter and degree of basal constriction. Several, parietal, discoid chloroplasts in outer cells only. Several parietal, discoid chloroplasts in outer cells only. Spermatangia develop as yellowish patches. Nearby small carpogonial branches entirely internal except thin trichogyne which protrudes beyond outer cell layer. Carposporophytes small, spherical masses of filaments forming large, ellipsoidal carpospores in central cavity; released by thallus deterioration and germinating into branched, uniseriate chantransia (= pseudochantransia) filaments. Chantransia stage produces gametophyte seasonally after meiosis. Chromosome numbers: L. fluviatilis n = (10)-18-19, L. mamillosa n = 20-21. Outer cell ultrastructure typical of florideophytes. Pit plug with 2 cap layers, outer one inflated. Axial cells with no chloroplasts and highly vacuolated. Carpogonia with basal nucleus, plentiful starch and vesicles. Spermatia released through narrow slit in wall.
Information contributed by: R.G. Sheath. The most recent alteration to this page was made on 20 Jan 2017 by M.D. Guiry.
Comments: Early 14C-labelled products in L. fluviatilis are floridoside, trehalose, sucrose and mannitol. L. mamillosa capable of internal CO2 transport; rate of photosynthesis proportional to CO2 concentration and inversely proportional to thallus radius. Cannot use HCO3- in photosynthesis but "knobbles" generate turbulence, thereby reducing inorganic carbon limitation at high pH. Genus widespread in temperature and boreal streams and rivers with typically high current velocities (up to 2 m s-1). Adapts to flow by developing dense turfs closely adherent to rocks and high breaking stress (910 Å 430 kN m-2 for L. fluviatilis). L. fluviatilis meiosis in chantransia state favored by low temperature . Several species common at high elevation up to 1200 m. L. fluviatilis tolerates 4-25%C, pH 4.1-8.2, specific conductance 10-300 mS cm-1. Occurs at low nutrient concentrations; L. mamillosa has membrane transporters with high affinity for ammonia and phosphate. Phosphorus content of L. fluviatilis in Swedish stream 0.48%. This species tolerant of zinc up to 1.16 mg 1-1. Not common in grazer gut contents, but larvae of caddisfly Dibusa use for food and case building. Lemanea and Audouinella hermannii commonly associated in Europe and North America. In a Rhode Island river, growth and reproduction of L. fluviatilis confined to April-August, after which thallus deteriorates and carpospores released; between September and March remnants remain. L. fluviatilis and L. mamillosa sold in India as food stuff called Nungham, meaning “hair of stones”.
Numbers of names and species: There are 37 species names in the database at present, as well as 11 infraspecific names. Of the species names, 16 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Click here to also show infraspecific names in the list below.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 28 December 2000 by M.D. Guiry
Verified by: 20 January 2017 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=42775
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 21 November 2019.