''Halophila'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
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 in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
''
Hydrocharitaceae'', the tape-grasses. It was described as a genus in 1806. The number of its contained species, and its own placement in the order
Alismatales, has evolved.
Description
These oceanic herbs grow underwater and have creeping stoloniferous stems and leafy nodes.
Unlike other seagrasses, the leaves of some species of ''Halophila'' do not have basal sheaths (i.e. the bases of the leaves do not wrap around the stem to form a sheath).
The flowers are unisexual. The male flowers are borne on stems. The parts occur in multiples of three along a single row.
The female flowers do not have stalks. They are divided into three segments. The single chambered ovary has a long beak. The three style are long and simple. The ovules are attached on top of three placentas.
The fruit is included in the bract surrounding the inflorescence (the spathe) and crowned by a beak. They have many seeds and thick embryos.
Distribution
This genus is widespread in tropical waters, the distribution range also extends to subtropical and temperate waters primarily the Indian and Pacific Oceans but also the Mediterranean and Caribbean Seas and the Gulf of Mexico.
It is found growing off the coasts of Africa, India, Australia and the Pacific Islands.
Naming
The Latin
specific epithet
In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
''halophila'' refers to salt loving.
Species
Species accepted by the
Kew Botanical Garden.
[
# '' Halophila australis'' - southern Australia
# ''Halophila baillonii'' - Caribbean, North and South America
# '' Halophila beccarii'' - South + East + Southeast Asia
# '' Halophila capricorni'' - ]New Caledonia
New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...
, islands in Coral Sea
The Coral Sea () is a marginal sea of the Pacific Ocean, South Pacific off the northeast coast of Australia, and classified as an Interim Biogeographic Regionalisation for Australia, interim Australian bioregion. The Coral Sea extends down t ...
# '' Halophila decipiens'' - shores of Indian Ocean and Pacific Ocean; Caribbean, Gulf of Mexico
# '' Halophila engelmannii'' - Mexico, Costa Rica, Bahamas, Cayman Islands, Cuba, United States ( PR, FL, LA, TX)
# '' Halophila gaudichaudii'' - Indian Ocean, western Pacific
# '' Halophila hawaiiana'' - Hawaii
# '' Halophila major'' - Japan, Taiwan, Southeast Asia, Caroline Is, Sri Lanka
# '' Halophila mikii'' - Japan
# '' Halophila minor'' - Indian Ocean, western Pacific
# '' Halophila nipponica'' (syn. ''Halophila japonica'')- Korea, Japan
# '' Halophila okinawensis'' - Nansei-shoto
# '' Halophila ovalis'' - Red Sea, Indian Ocean, western Pacific
# '' Halophila spinulosa'' - Southeast Asia, North Australia, New Guinea
# '' Halophila stipulacea'' - Red Sea, Indian Ocean, invasive in the Caribbean
# '' Halophila sulawesii'' - Sulawesi
# '' Halophila tricostata'' - Queensland
References
External links
*
Western Australia Seagrass web page for Halophila
*
{{Taxonbar, from=Q2688882
Hydrocharitaceae genera