Callitriche antarctica
Encyclopedia
Callitriche antarctica , commonly known as the Antarctic water-starwort, is a small, prostrate plant
with tiny yellow flowers in the plantain
family (though sometimes placed in its own family – Callitrichaceae). It is found in wet places on many subantarctic
islands and has a wide circumantarctic
distribution, something reflected in its specific epithet.
, with freely branched stems, rooting at the nodes. It has a similar appearance to watercress
. The small, fleshy, spathulate leaves
are usually 3–5 mm long and 1–2.5 mm wide. Flowering occurs from September to March. The yellowish to dull brown fruits are about a millimetre in diameter.
, Heard
and Macquarie Island
s, the Auckland
, Antipodes
, Kerguelen
, Prince Edward
, Crozet
and Falkland Islands, as well as on South Georgia and Tierra del Fuego
. The plant may be locally common, especially in boggy areas, along streams and around freshwater pools.
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
with tiny yellow flowers in the plantain
Plantaginaceae
Plantaginaceae Juss. or plantain family, are a family of flowering plants in the order Lamiales. The type genus is Plantago L..In older classifications it used to be the only family of the order Plantaginales, but numerous phylogenetic studies, summarized by the Angiosperm Phylogeny Group, have...
family (though sometimes placed in its own family – Callitrichaceae). It is found in wet places on many subantarctic
Subantarctic
The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and...
islands and has a wide circumantarctic
Antarctic Circumpolar Current
The Antarctic Circumpolar Current is an ocean current that flows from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and, at approximately 125 Sverdrups, the largest ocean current...
distribution, something reflected in its specific epithet.
Description
The starwort is a prostrate, mat-forming herbHerbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
, with freely branched stems, rooting at the nodes. It has a similar appearance to watercress
Watercress
Watercresses are fast-growing, aquatic or semi-aquatic, perennial plants native from Europe to central Asia, and one of the oldest known leaf vegetables consumed by human beings...
. The small, fleshy, spathulate leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are usually 3–5 mm long and 1–2.5 mm wide. Flowering occurs from September to March. The yellowish to dull brown fruits are about a millimetre in diameter.
Distribution and habitat
The starwort occurs on CampbellCampbell Island, New Zealand
Campbell Island is a remote, subantarctic island of New Zealand and the main island of the Campbell Island group. It covers of the group's , and is surrounded by numerous stacks, rocks and islets like Dent Island, Folly Island , Isle de Jeanette Marie, and Jacquemart Island, the latter being the...
, Heard
Heard Island and McDonald Islands
The Heard Island and McDonald Islands are an Australian external territory and volcanic group of barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is in area and it has of coastline...
and Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
s, the Auckland
Auckland Islands
The Auckland Islands are an archipelago of the New Zealand Sub-Antarctic Islands and include Auckland Island, Adams Island, Enderby Island, Disappointment Island, Ewing Island, Rose Island, Dundas Island and Green Island, with a combined area of...
, Antipodes
Antipodes Islands
The Antipodes Islands are inhospitable volcanic islands to the south of—and territorially part of—New Zealand...
, Kerguelen
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
, Prince Edward
Prince Edward Islands
The Prince Edward Islands are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. The islands, named Marion Island and Prince Edward Island, are located at ....
, Crozet
Crozet Islands
The Crozet Islands are a sub-antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands.-Geography:...
and Falkland Islands, as well as on South Georgia and Tierra del Fuego
Tierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
. The plant may be locally common, especially in boggy areas, along streams and around freshwater pools.