''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
stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filame ...
s 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.
Molecular evidence supports ''Allionia'' as sister to the least inclusive clade containing both ''
Boerhavia'' and ''Cyphomeris.''
The range of ''
Allionia incarnata''
L. includes
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, 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
Carlo Allioni (23 September 1728 in Turin – 30 July 1804 in Turin) was an Italian physician and professor of botany at the University of Turin. His most important work was ''Flora Pedemontana, sive enumeratio methodica stirpium indigenarum P ...
(1725–1804).
References
Flora of North America: ''Allionia''
Nyctaginaceae
Caryophyllales genera
{{Caryophyllales-stub