Zosteraceae (one of the four seagrasses families, Kubitzki ed. 1998) is a family of
marine perennial
In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s found in
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...
and
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...
coastal waters, with the highest diversity located around Korea and Japan. Most
seagrass
Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...
es complete their entire
life cycle under water, having filamentous
pollen
Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...
especially adapted to dispersion in an aquatic environment and ribbon-like leaves that lack
stomata
In botany, a stoma (: stomata, from Greek ''στόμα'', "mouth"), also called a stomate (: stomates), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange between the internal air spa ...
. Seagrasses are
herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition of ...
and have prominent creeping
rhizome
In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...
s. A distinctive characteristic of the family is the presence of characteristic retinacules, which are present in all species except members of ''Zostera'' subgenus ''Zostera''.
Zosteraceae has long been accepted by taxonomists as
monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
. The
APG II system of 2003 recognizes this family and places it in the
monocot order
Alismatales. The family contains approximately twenty-two species divided between two genera, ''
Phyllospadix'' and ''
Zostera'' totalling 22 known species (Christenhusz & Byng 2016
). ''
Zostera'' contains three subgenera: ''
Heterozostera'' (formerly considered a separate genus ), ''Zostera'' and ''Zosterella''.
Zosteraceae is closely related to
Potamogetonaceae, a family of freshwater aquatics.
''Zosteraceae'' is a
conserved name
A conserved name or ''nomen conservandum'' (plural ''nomina conservanda'', abbreviated as ''nom. cons.'') is a scientific name that has specific nomenclatural protection. That is, the name is retained, even though it violates one or more rules wh ...
.
Taxonomy
Marine grasses families: Zosteraceae,
Cymodoceaceae
Cymodoceaceae is a family of flowering plants, sometimes known as the "manatee-grass family", which includes only marine species.
The 2016 APG IV does recognize Cymodoceaceae and places it in the order Alismatales, in the clade monocots. The ...
,
Ruppiaceae and
Posidoniaceae. Related families:
Potamogetonaceae and sometimes including
Zannichelliaceae.
References
Further reading
Waycott, M, McMahon, K, Lavery, P 2014, A Guide to Southern Temperate Seagrasses, CSIRO Publishing, Melbourne,
External links
Zosteraceaein L. Watson and M.J. Dallwitz (1992 onwards).
The families of flowering plants descriptions, illustrations, identification, information retrieval. Version: 27 April 2006.
Zosteraceae in the ''Flora of North America''NCBI Taxonomy Browserlinks at CSDL, Texas
{{Authority control
Alismatales families