Allionia

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Ordo: Caryophyllales

Familia: Nyctaginaceae
Tribus: Nyctagineae
Genus: Allionia
Species: A. choisyi - A. incarnata

Name

Allionia L., Syst. Nat., ed. 10. 2: 883 (890, 1361). (1759) nom. et typ. cons.

Type species: Allionia incarnata L. Syst. Nat., ed. 10. 2: 890. (1759)

Synonyms

Heterotypic
Wedelia Loefl. Iter Hispan. 176, 180. (1758) non Wedelia Jacq. (1760) nom. cons. (Asteraceae)
Wedeliella Cockerell Torreya 9: 167. (1909) nom. rej. against Wedelia Loefl. (1758)

Homonyms

Allionia Loefl. Iter Hispan. 181. (1758) nom. rej.

References

Linnaeus, C. von 1759. Systema Naturae, Editio Decima 890.
Hassler, M. 2017. Allionia. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2017. Species 2000 & ITIS Catalogue of Life. Published on the internet. Accessed: 2017 May 12. Reference page.
International Plant Names Index. 2017. Allionia. Published online. Accessed: 12 May 2017.
Tropicos.org 2017. Allionia. Missouri Botanical Garden. Published on the internet. Accessed: 2017 May 12.

Vernacular names
English: Windmills, Trailing Four o'Clock
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 flower.

The plants are finely pubescent 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. 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.[1]

Molecular evidence supports Allionia as sister to the least inclusive clade containing both Boerhavia and Cyphomeris.[1]
Close-up showing triple arrangement of the flowers

The range of Allionia incarnata L. includes North America, the West Indies, Central America, and South America, while Allionia choisyi Standley is more restricted in North America, occurring only in Arizona, Utah, New Mexico, and Texas. 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 named the genus after Italian botanist Carlo Allioni (1725–1804).
References
Wikimedia Commons has media related to Allionia incarnata.

Douglas, Norman A.; Manos, Paul S. (2007). "Molecular phylogeny of Nyctaginaceae: taxonomy, biogeography, and characters associated with a radiation of xerophytic genera in North America". American Journal of Botany. 94 (5): 856–872. doi:10.3732/ajb.94.5.856. ISSN 1537-2197.

Flora of North America: Allionia