163,924 species and infraspecific names are in the database, 22,783 images, 63,106 bibliographic items, 484,278 distributional records.

Althenia F.Petit, 1829

Classification:
Empire Eukaryota
Kingdom Plantae
Phylum Tracheophyta
Subphylum Euphyllophytina
Infraphylum Spermatophytae
Superclass Angiospermae
Class Monocots
Subclass Alismatidae
Order Alismatales
Family Potamogetonaceae

Holotype species: Althenia filiformis Petit

Original publication and holotype designation: Petit, F. (1829). Althenia novi plantarum generis descriptio. Annales des Sciences d'Observation 1: 451-456.

Taxonomic status: currently recognized as a distinct genus.

Gender: This genus name is currently treated as feminine.

Most recent taxonomic treatment adopted: Ito, Y., Tanaka, N., García-Murillo, P. & Muasya, A.M. (2016). A new delimitation of the Afro-Eurasian plant genus Althenia to include its Australasian relative, Lepilaena (Potamogetonaceae). Evidence from DNA and morphological data. Molecular Phylogenetics and Evolution 98: 261-270, 4 figs.

Description: Monoecious or dioecious, annual or perennial herbs. Leaves alternate, with floral leaves often apparently subopposite and frequently crowded toward stem apex, basal sheath present; sheath or stipule adnate to leaf blade for most of its length, with or without conspicuous nerves; ligule well developed, frequently bifid; blade linear, with or without lateral nerves. Flowers sessile or pedicellate. Male flowers consisting of single stamen and a 3- segmented perianth; pedicel short at first, elongating at anthesis; anther mass sessile or subsessile, with 2–6 locules united longitudinally and dorsally. Female flowers with a perianth divided into 3 segments; carpels 3, free; style slender; stigma symmetrical or asymmetrical, peltate-, feathery (laciniate)-, to funnel-shaped. Fruit an achene.

Information contributed by: Ito & al. (2016). The most recent alteration to this page was made on 17 Nov 2020 by M.D. Guiry.

Numbers of names and species: There are 5 species names in the database at present, of which 5 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.

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.

Created: 23 April 2002 by M.D. Guiry

Verified by: 17 November 2020 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=44020

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 27 October 2021.

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