Polycnemoideae

Last updated • 3 min readFrom Wikipedia, The Free Encyclopedia

Polycnemoideae
Nitrophila occidentalis 2.jpg
Nitrophila occidentalis
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Amaranthaceae
Subfamily: Polycnemoideae
Ulbr.
Genera

4 genera, see text

The Polycnemoideae are a small subfamily of plants in the family Amaranthaceae, representing a basal evolutionary lineage. The few relictual species are distributed in Eurasia and North Africa, North America, and Australia.

Contents

Description

The subfamily Polycnemoideae comprises small herbs; some species are weakly lignified and grow shrublike. The subfamily is distinguishable from all other members of Amaranthaceae by normal secondary growth. The alternate or opposite leaves are often linear or subulate. The stomata of the leaves are arranged in parallel to the midveins. [1]

The bisexual flowers are sitting solitary in the axil of a bract and two bracteoles. The inconspicuous perianth is formed of chartaceous, scarious, white or pinkish tepals. One to five stamens are present with their filaments united in a short but distinct filament tube (like in subfamily Amaranthoideae). Anthers are with only one lobe and two pollen sacs (bilocular, like in subfamily Gomphrenoideae). In fruit, the tepals are never conspicuously modified. [1]

Photosynthesis pathway

The Polycnemoideae are all C3-plants. This is considered a primary character. [1]

Distribution and evolution

The Polycnemoideae are distributed in the temperate regions of Eurasia (central and southern Europe, northwestern Africa, Central Asia), North America, and Australia. [1]

Polycnemoideae began to diverge from Amaranthaceae s.str. in Eocene. At the edge from Eocene to Oligocene, the subfamily split into a lineage on the Northern Hemisphere, which was the ancestor of Polycnemum , and a lineage predominantly occurring on the Southern Hemisphere with the ancestors of Nitrophila , Hemichroa , and Surreya . An antarctic connection of these southern ancestors is assumed. The genus Nitrophila developed in South America and dispersed later to North America. The genera of the subfamily diversified during Miocene and Pliocene, with only a few rare species that seem to be relictual. [2]

Systematics

Polycnemum arvense, Illustration Polycnemum arvense Sturm.png
Polycnemum arvense , Illustration

The intrafamilial position of the Polycnemoideae has long been a matter of dispute. The taxon was recognized in 1827 as Tribus Polycnemeae within the family Chenopodiaceae by Dumortier (In Florula Belgica). Later, it was treated as belonging to the family Amaranthaceae in 1849 by Moquin-Tandon (in Prodromus systematis naturalis.... Vol 13). Oskar Eberhard Ulbrich raised it to subfamilial level in 1934, again within Chenopodiaceae (in Engler & Prantl: Die natürlichen Pflanzenfamilien. Vol 16c). Today, both families are included in Amaranthaceae s.l. [1]

Phylogenetic research has revealed the Polycnemoideae represent a basal lineage of evolution within the family Amaranthaceae. [1]

The Polycnemoideae comprise only one tribe, Tribus Polycnemeae, [3] with four genera and 13 species: [2]

Related Research Articles

<span class="mw-page-title-main">Amaranthaceae</span> Family of flowering plants

Amaranthaceae is a family of flowering plants commonly known as the amaranth family, in reference to its type genus Amaranthus. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, making it the most species-rich lineage within its parent order, Caryophyllales.

Sarcocornia is a formerly recognized genus of flowering plants in the amaranth family, Amaranthaceae. Species are known commonly as samphires, glassworts, or saltworts. Molecular phylogenetic studies have shown that when separated from Salicornia, the genus is paraphyletic, since Salicornia is embedded within it, and Sarcocornia has now been merged into a more broadly circumscribed Salicornia. When separated from Salicornia, the genus has a cosmopolitan distribution, and is most diverse in the Cape Floristic Region of South Africa.

<span class="mw-page-title-main">Salicornioideae</span> Subfamily of flowering plants

The Salicornioideae are a subfamily of the flowering plant family Amaranthaceae. Important characters are succulent, often articulated stems, strongly reduced leaves, and flowers aggregated in thick, dense spike-shaped thyrses. These halophytic plants are distributed worldwide. Many are edible

<span class="mw-page-title-main">Salsoloideae</span> Subfamily of flowering plants

The Salsoloideae are a subfamily of the Amaranthaceae, formerly in family Chenopodiaceae.

<span class="mw-page-title-main">Chenopodioideae</span> Subfamily of flowering plants

The Chenopodioideae are a subfamily of the flowering plant family Amaranthaceae in the APG III system, which is largely based on molecular phylogeny, but were included – together with other subfamilies – in the family Chenopodiaceae, or goosefoot family, in the Cronquist system.

<i>Chenopodium</i> Genus of flowering plants in the amaranth family

Chenopodium is a genus of numerous species of perennial or annual herbaceous flowering plants known as the goosefoot, which occur almost anywhere in the world. It is placed in the family Amaranthaceae in the APG II system; older classification systems, notably the widely used Cronquist system, separate it and its relatives as Chenopodiaceae, but this leaves the rest of the Amaranthaceae polyphyletic. However, among the Amaranthaceae, the genus Chenopodium is the namesake member of the subfamily Chenopodioideae.

<i>Beta</i> (plant) Genus of flowering plants in the amaranth family Amaranthaceae

Beta is a genus in the flowering plant family Amaranthaceae. The best known member is the common beet, Beta vulgaris, but several other species are recognised. Almost all have common names containing the word "beet". Wild Beta species can be found throughout the Atlantic coast of Europe, the Mediterranean coastline, the Near East, and parts of Asia including India.

<i>Halothamnus</i> Genus of flowering plants

Halothamnus is a genus in the subfamily Salsoloideae of the family Amaranthaceae. The scientific name means "saltbush", from the Greek ἅλς 'salt' and θαμνος 'bush'. This refers either to salty habitats or to the accumulation of salt in the plants. The genus is distributed from Southwest and Central Asia to the Arabian peninsula and East Africa.

<span class="mw-page-title-main">Betoideae</span> Subfamily of flowering plants

The Betoideae are a small subfamily of the flowering plant amaranth family, Amaranthaceae sensu lato. Commonly known members include beet, sugar beet, chard, and mangelwurzel, which all are cultivars of Beta vulgaris.

<span class="mw-page-title-main">Camphorosmeae</span> Tribe of flowering plants

Camphorosmeae is a species-rich tribe of the Amaranthaceae, formerly Chenopodiaceae, with 20 genera and about 179 species. It is classified as a single tribe of subfamily Camphorosmoideae.

<span class="mw-page-title-main">Suaedoideae</span> Subfamily of flowering plants

The Suaedoideae are a subfamily of plants in the family Amaranthaceae.

<span class="mw-page-title-main">Corispermoideae</span> Subfamily of flowering plants

The Corispermoideae are a subfamily of the Amaranthaceae, formerly in family Chenopodiaceae.

<i>Dysphania</i> (plant) Genus of flowering plants

Dysphania is a genus of plants in the family Amaranthaceae. Species of the genus are found worldwide from the tropics and subtropics to warm-temperate regions.

<i>Halostachys</i> Genus of flowering plants

Halostachys is a genus of flowering plants in the plant family Amaranthaceae, containing a single species, Halostachys caspica. The plants are small to medium halophytic shrubs with apparently jointed fleshy stems and scale-like leaves. They are native to western and central Asia and northern China.

<i>Kalidium</i> Genus of flowering plants

Kalidium is a genus of flowering plants in the plant family Amaranthaceae. The species are shrubby halophytes distributed in Southeast Europe, Southwest Asia and Central Asia to China.

<i>Heterostachys</i> Genus of flowering plants

Heterostachys is a genus of flowering plants in the plant family Amaranthaceae. The two species are shrubby halophytes native to South America and Central America.

<i>Allenrolfea</i> Genus of flowering plants

Allenrolfea is a genus of shrubs in the family Amaranthaceae. The genus was named for the English botanist Robert Allen Rolfe. There are three species, ranging from North America to South America.

Arthrocnemum was a genus of shrubs in the family Amaranthaceae. Two or three species were included in the genus. They are halophytes with fleshy, apparently articulated plant stems and reduced leaves and flowers.

<i>Patellifolia</i> Genus of flowering plants

Patellifolia is a genus of flowering plants in the subfamily Betoideae of the family Amaranthaceae. These are mostly procumbent herbs occurring in the Western Mediterranean region and Macaronesia, with some isolated occurrences in North Africa and at the Horn of Africa. They are interesting as crop wild relatives of sugar beet.

<i>Surreya</i> Genus of flowering plants

Surreya is a genus of flowering plants belonging to the family Amaranthaceae. It is also in the Polycnemoideae subfamily.

References

  1. 1 2 3 4 5 6 Gudrun Kadereit, Thomas Borsch, K. Weising, and Helmut Freitag (2003): Phylogeny of Amaranthaceae and Chenopodiaceae and the evolution of C4 photosynthesis. - In: Int. J. Plant Sci. 164(6): p. 959–986.
  2. 1 2 3 4 5 6 Rüdiger Masson & Gudrun Kadereit (2013): Phylogeny of Polycnemoideae (Amaranthaceae): Implications for biogeography, character evolution and taxonomy. Taxon 62 (1): 100-111.
  3. Polycnemoideae, Germplasm Resources Information Network - (GRIN) Online Database