''Allenrolfea'' 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 shrubs 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 named for the English botanist

Robert Allen Rolfe Robert Allen Rolfe (1855, Wilford, Nottinghamshire – 1921, Richmond, London, Richmond, Surrey) was an English botanist specialising in the study of orchids. For a time he worked in the gardens at Welbeck Abbey. He entered Kew in 1879 and became ...

. There are three species, ranging from North America to South America.

Description

The species of ''Allenrolfea'' are

subshrub A subshrub (Latin ''suffrutex'') or undershrub is either a small shrub (e.g. prostrate shrubs) or a perennial that is largely herbaceous but slightly woody at the base (e.g. garden pink and florist's chrysanthemum). The term is often interch ...

s or

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s with erect or decumbent growth. The stems are much branched, succulent, glabrous and appear to be articulated. 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, ...

are sessile and stem-clasping, fleshy, glabrous, their blades reduced to small, broadly triangular scales, with entire margins and acute apex. The inflorescences are terminal spikes with spirally arranged flowers.

Cymes In botany, an inflorescence is a group or cluster of flowers arranged on a plant's 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 main axis ( ped ...

of three or five flowers are sitting in the axils of deciduous, peltate, fleshy

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

s. The flowers are bisexual. The perianth consists of 4-5 joined

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s, their lobes angled and truncate distally. There are 1-2

stamen 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 filament ...

s exserting the flower and an ovary with 2(-3) stigmas. The fruit in an ovoid, compressed utricle with membranous

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 ...

. The erect

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

is brown or reddish brown, oblong, with smooth surface. It contains copious

perisperm In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fema ...

(feeding tissue), and a half-annular embryo. The chromosome basic number is x = 9.

Occurrence

The species of ''Allenrolfea'' are distributed in

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 ...

(southwestern United States), Mexico,

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

(

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

). They grow on

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

soils, on sandy hummocks in salt playas, and in mud flats. In the USA they are found at about 1000–1700 m above sea level.

Systematics

The first publication of the genus ''Allenrolfea'' was made in 1891 by

Otto Kuntze Carl Ernst Otto Kuntze (23 June 1843 – 27 January 1907) was a German botanist. Biography Otto Kuntze was born in Leipzig. An apothecary in his early career, he published an essay entitled ''Pocket Fauna of Leipzig''. Between 1863 and 1866, he ...

. With this description, he replaced the invalid name ''Spirostachys'' from 1874, (which is illegitimate, as '' Spirostachys'' already existed since 1850). The type species is ''Allenrolfea occidentalis''. The genus consists of three species: *''

Allenrolfea occidentalis ''Allenrolfea occidentalis'', the iodine bush, is a low-lying shrub of the Southwestern United States, California, Idaho, and northern Mexico.Shultz, L.M.: 'eFloras 2008''Allenrolfea occidentalis'' in Flora of North America Missouri Botanical Ga ...

'' , in North America (southwestern USA: Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, Utah), and in Mexico. *'' Allenrolfea patagonica'' ,

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

. *'' Allenrolfea vaginata'' , endemic to Argentina. ''Allenrolfea'' is a near relative of the genus '' Heterostachys'', which also is distributed in America. Their common lineage seems to have evolved early in the evolution of the subfamily

Salicornioideae The Salicornioideae are a subfamily of the flowering plant family Amaranthaceae (''sensu lato'', including the Chenopodiaceae). Important characters are succulent, often articulated stems, strongly reduced leaves, and flowers aggregated in thick, ...

, dating back to the Early to Middle

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

. It might have reached America long before the other American taxa of Salicornioideae.

References

Kadereit, G., Mucina, L., & Freitag, H.: ''Phylogeny of Salicornioideae (Chenopodiaceae): diversification, biogeography, and evolutionary trends in leaf and flower morphology'', In: ''Taxon'', Volume 55 (3), 2006, p. 624, 635. Kuntze, C.E.O.: ''Revisio Generum Plantarum'' 2, 1891, p. 545-546
first description scanned at BHL
/ref> Shultz, L.M.: 'eFloras 2008
''Allenrolfea'' in Flora of North America
Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA. F.O. Zuloaga, O. Morrone, M.J. Belgrano, C. Marticorena, E. Marchesi. (Hrsg.) 2008. ''Catálogo de las plantas vasculares del Cono Sur.'' Monogr. Syst. Bot. Missouri Bot. Gard. 107(1–3): i–xcvi, 1–3348
''Allenrolfea patagonica''
F.O. Zuloaga, O. Morrone, M.J. Belgrano, C. Marticorena, E. Marchesi. (Hrsg.) 2008. ''Catálogo de las plantas vasculares del Cono Sur.'' Monogr. Syst. Bot. Missouri Bot. Gard. 107(1–3): i–xcvi, 1–3348
''Allenrolfea vaginata''

External links

* *
USDA Plants Profile

Illustration of ''Allenrolfea patagonica'' at ''Instituto de Botanica Darwinion''

Illustration of ''Allenrolfea vaginata'' at ''Instituto de Botanica Darwinion''
{{Authority control Amaranthaceae Amaranthaceae genera