''Chenopodiastrum'' is a genus of

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 ...

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 in the family

Amaranthaceae 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, maki ...

. The genus was formally described in 2012. The five species occur in both the Old World and North America.

Description

The species in genus ''Chenopodiastrum'' are non-aromatic

annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), a ...

herbs. Young plants have vesicular

trichome Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

s, that later collapse and fall down, thus plants becoming glabrescent. Stems grow erect, with lateral branches. The alternate

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

have a petiole and a thickish triangular, ovate, rhombic-ovate to lanceolate leaf blade. The leaf margin can be irregularly dentate or lobed, or pinnatifid with narrow dentate lobes. The axillary and terminal

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s consist of small dense glomerules of flowers, arranged spicately or paniculately. Flowers are

bisexual Bisexuality is romantic attraction, sexual attraction, or sexual behavior toward both males and females. It may also be defined as the attraction to more than one gender, to people of both the same and different gender, or the attraction t ...

pistillate Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ...

. They contain 5 basally connate

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower. It is a structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepal ...

segments with a prominent keel near the apex, and a characteristic strong midrib visible from the inside; a circle of 5

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

; and an ovary with 2 stigmas. In fruit, the perianth lobes enclose the fruit or spread. The membraneous

pericarp Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Fruitlike structures may develop directly from the seed itself rather th ...

adheres firmly to the seed. The horizontally orientated seeds are lenticular. The black seed coat is often prominently pitted, sometimes rugulose or nearly smooth.

Taxonomy

The genus ''Chenopodiastrum'' was described in 2012 by Suzy Fuentes-Bazan, Pertti Uotila und Thomas Borsch (in: A novel phylogeny-based generic classification for ''Chenopodium'' sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). in ''Willdenowia'' 42, p. 14). After

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

research, this group of species had to be separated from genus ''

Chenopodium ''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 classifica ...

'', that would otherwise have been

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

. The genus ''Chenopodiastrum'' belongs to the same tribe as ''Chenopodium'', Tribus Atripliceae. ''Chenopodiastrum'' consists of 5 species, occurring in

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

, and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Distribution

The species are distributed as follows: *'' Chenopodiastrum badachschanicum'' (Tzvelev) S.Fuentes, Uotila & Borsch, (syn. ''Chenopodium badachschanicum'' Tzvelev): In

Middle Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian suffix " -sta ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

, northeastern

Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran borde ...

, northern

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

, northern

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

Nepal Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China Ch ...

.''Chenopodium badachschanicum''
In: Helmut Freitag et al.: ''Chenopodiaceae''. In: ''Flora of Pakistan'', Volume 204 - Missouri Botanical Garden Press & University of Karachi. *'' Chenopodiastrum coronopus'' (Moq.) S.Fuentes, Uotila & Borsch, (syn. ''Chenopodium coronopus'' Moq.): endemic on

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

, Ilhas Selvagens, and probably

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

.Pertti Uotila, 2011: ''Chenopodiaceae (pro parte majore):'
''Chenopodium coronopus''
– In: ''Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity'', retrieved 2 July 2013 *'' Chenopodiastrum hybridum'' (L.) S.Fuentes, Uotila & Borsch (syn. ''Chenopodium hybridum'' L.): in Europe, India and from temperate Asia to China. *'' Chenopodiastrum murale'' (L) S.Fuentes, Uotila & Borsch (syn. ''Chenopodium murale'' L. ): in Europe, North Africa and

Southwest Asia West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenia ...

. *'' Chenopodiastrum simplex'' (Torr.) S.Fuentes, Uotila & Borsch (syn. ''Chenopodium hybridum'' var. ''simplex'' Torr.): in North America.

References

External links

*
''Chenopodiastrum''
at Tropicos {{Taxonbar, from=Q13847552 Chenopodioideae Amaranthaceae genera