{{Short description|Genus of flowering plants}} {{Automatic taxobox |image = Allenrolfea occidentalis 4.jpg |image_caption = ''Allenrolfea occidentalis'' |taxon = Allenrolfea |authority = Kuntze |subdivision_ranks = Species |subdivision = *''Allenrolfea occidentalis'' {{au|(S.Watson) Kuntze}} *''Allenrolfea patagonica'' {{au|(Moq.) Kuntze}} *''Allenrolfea vaginata'' {{au|(Griseb.) Kuntze}} }}
'''''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.<ref name="FNA" /> [[File:1 Halopeplis patagonica, Allenrolfea patagonica.jpg|thumb|''Allenrolfea patagonica'']]
== Description == The species of ''Allenrolfea'' are subshrubs or shrubs with erect or decumbent growth. The stems are much branched, succulent, glabrous and appear to be articulated. The alternate leaves are sessile and stem-clasping, fleshy, glabrous, their blades reduced to small, broadly triangular scales, with entire margins and acute apex.<ref name="FNA" />
The inflorescences are terminal spikes with spirally arranged flowers. Cymes of three or five flowers are sitting in the axils of deciduous, peltate, fleshy bracts. The flowers are bisexual. The perianth consists of 4-5 joined tepals, their lobes angled and truncate distally. There are 1-2 stamens exserting the flower and an ovary with 2(-3) stigmas.<ref name="FNA" />
The fruit in an ovoid, compressed utricle with membranous pericarp. The erect seed is brown or reddish brown, oblong, with smooth surface. It contains copious perisperm (feeding tissue),<ref name="FNA" /> and a half-annular embryo.<ref name="Kadereit" />
The chromosome basic number is x = 9.<ref name="FNA" />
== Occurrence == The species of ''Allenrolfea'' are distributed in North America (southwestern United States),<ref name="FNA" /> Mexico, Central America, and South America (Argentina).<ref name="Kadereit" /><ref name="Zuloaga p" /><ref name="Zuloaga v" /> They grow on alkaline 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.<ref name="FNA" />
== Systematics == The first publication of the genus ''Allenrolfea'' was made in 1891 by Otto Kuntze.<ref name="Kuntze" /> With this description, he replaced the invalid name ''Spirostachys'' {{au|S.Watson}} from 1874, (which is illegitimate, as ''Spirostachys'' {{au|Sond.}} already existed since 1850). The type species is ''Allenrolfea occidentalis''.<ref name="tropicos" />
The genus consists of three species:<ref name="FNA" /><ref name="Kadereit" /><ref>{{cite web|title=Allenrolfea|url=http://www.theplantlist.org/1.1/browse/A/Amaranthaceae/Allenrolfea/|website=The Plant List|access-date=4 August 2016|date=2013}}</ref> *''Allenrolfea occidentalis'' {{au|(S.Watson) Kuntze}}, in North America (southwestern USA: Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, Utah), and in Mexico.<ref name="FNA" /> *''Allenrolfea patagonica'' {{au|(Moq.) Kuntze}}, endemic in Argentina.<ref name="Zuloaga p" /> *''Allenrolfea vaginata'' {{au|(Griseb.) Kuntze}}, endemic to Argentina.<ref name="Zuloaga v" />
''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, dating back to the Early to Middle Oligocene. It might have reached America long before the other American taxa of Salicornioideae.<ref name="Kadereit" />
== References == <references> <ref name="Kadereit">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.</ref> <ref name="Kuntze">Kuntze, C.E.O.: ''Revisio Generum Plantarum'' 2, 1891, p. 545-546. [https://www.biodiversitylibrary.org/page/3967#page/171/mode/1up first description scanned at BHL]</ref> <ref name="FNA">Shultz, L.M.: 'eFloras 2008. [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=101076 ''Allenrolfea'' in Flora of North America]. Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.</ref> <ref name="tropicos">{{Tropicos|40010115|Allenrolfea|||accessdate=2016-08-06}}</ref> <ref name="Zuloaga p">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. [http://www2.darwin.edu.ar/Proyectos/FloraArgentina/DetalleEspecie.asp?forma=&variedad=&subespecie=&especie=patagonica&genero=Allenrolfea&espcod=5644 ''Allenrolfea patagonica''].</ref> <ref name="Zuloaga v">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. [http://www2.darwin.edu.ar/Proyectos/FloraArgentina/DetalleEspecie.asp?forma=&variedad=&subespecie=&especie=vaginata&genero=Allenrolfea&espcod=5645 ''Allenrolfea vaginata''].</ref> </references>
==External links== *{{Commons-inline}} *{{Wikispecies-inline|Allenrolfea|''Allenrolfea''}} *[https://plants.usda.gov/java/profile?symbol=ALLEN USDA Plants Profile] * [http://www2.darwin.edu.ar/ImagenesIris/Allenrolfea%20patagonica%2001.jpg Illustration of ''Allenrolfea patagonica'' at ''Instituto de Botanica Darwinion'']. * [http://www2.darwin.edu.ar/ImagenesIris/Allenrolfea%20vaginata_INTA_F%20ARG.jpg Illustration of ''Allenrolfea vaginata'' at ''Instituto de Botanica Darwinion''].
{{Taxonbar|from=Q3736031}} {{Authority control}}
Category:Amaranthaceae Category:Amaranthaceae genera