''Allionia'', commonly known as windmills or trailing four o'clock, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of two plant species widespread in the Western Hemisphere. Both species are unusual in their blooms, which consist of three separate flowers appearing to be a single flower. The plants are finely

pubescent The adjective pubescent may describe: * people or animals undergoing puberty * plants that are hairy, covered in trichomes * insects that are covered in setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a ...

annuals or short-lived perennials, with trailing, recumbent stems up to one metre in length, often threading through other vegetation. The leaves range from oval to oblong, under 4 cm long. The inflorescences are axillary, consisting of three flowers with petals varying in color from red to purple, symmetrically arranged and superficially appearing to be a single flower 3–15 mm across. The individual flowers are bisexual and bilaterally symmetric with a distinct oblique funnel. The 5–7 stamens may be somewhat exserted, along with the

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

. The boat-shaped anthocarps are morphologically distinct from those of other members of their family. These fruits have five ribs and two rows of inward pointing teeth on the concave side. Molecular evidence supports ''Allionia'' as sister to the least inclusive clade containing both ''

Boerhavia ''Boerhavia'' is a genus of over 100 species in the Nyctaginaceae family. The genus was named for Herman Boerhaave, a Dutch botanist, and the genus name is frequently misspelled "''Boerhaavia''". Common names include spiderlings and hogweeds. T ...

'' and ''Cyphomeris.'' The range of ''

Allionia incarnata ''Allionia incarnata'' is a flowering plant in the four o'clock family (Nyctaginaceae Nyctaginaceae, the four o'clock family, is a family of around 33 genera and 290 species of flowering plants, widely distributed in tropical and subtropical ...

'' L. includes North America, the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

, while ''

Allionia choisyi ''Allionia'', commonly known as windmills or trailing four o'clock, is a genus of two plant species widespread in the Western Hemisphere. Both species are unusual in their blooms, which consist of three separate flowers appearing to be a single f ...

'' Standley is more restricted in North America, occurring only in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

, and

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

. The two species can only be reliably distinguished by characteristics of their fruits, and even those may be found intergraded where the species' ranges overlap.

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

named the genus after Italian botanist Carlo Allioni (1725–1804).

References

Flora of North America: ''Allionia''
Nyctaginaceae Caryophyllales genera {{Caryophyllales-stub