''Thingia'' is a

monospecific In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the family

Montiaceae Montiaceae are a family of flowering plants, comprising about 14 genera with about 230 known species, ranging from small herbaceous plants to shrubs. The family has a cosmopolitan distribution. The family Montiaceae was newly adopted in the APG ...

comprised only by the species ''Thingia ambigua'', known as desert pussypaws. It is native to northwestern Mexico,

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, and is found commonly on sandy or silty soil. The sole species of the genus has been housed under several genera before it was split into ''Thingia'': '' Claytonia'' in 1882, '' Calandrinia'' in 1893, and ''

Cistanthe ''Cistanthe'' is a plant genus which includes most plants known as pussypaws. These are small, succulent flowering plants which often bear brightly colored flowers, though they vary quite a bit between species in appearance. Some species have flo ...

'' in 1990. DNA evidence demonstrated that the relationship of ''Thingia ambigua'', then ''Cistanthe ambigua'', to the next closest relative in ''Cistanthe'', '' C. tweedyi'', was actually disjointed. It was found that the two species were most closely related to completely separate South American taxa.

Description

''Thingia ambigua'' is an

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...

with fleshy roots. It has stems long that grow outwards and upright. Its leaves are narrow and clasp the stem at their base; each leaf blade is long. It has dense clusters of flowers, each with 3–5 white petals. They have 5–10

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 with a yellow-colored anther and three stigmas with a

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

that is long. The seeds are oval-shaped and black in color. The species flowers from November to February. The genus has several distinctive characteristics that differentiate it from closely related taxa. It has three

carpels Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ...

, instead of the two possessed by species of '' Calyptridium'' and '' Philippiamra''. While species of '' Lenzia'' also have three carpels, their foliage differs from that of ''Thingia''. Plants of ''Thingia'' have leafy stems and complex flower structures, whereas those in ''Lenzia'' have almost no visible stems and only solitary flowers. Another difference is in the

veins Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal c ...

of the leaves: ''Thingia'' has a three-dimensional vein arrangement, where the veins of the other genera are arranged in a two-dimensional pattern.

References

{{Taxonbar, from1=Q123482339, from2=Q123482355 Flora of Arizona Flora of Mexico Flora of California Montiaceae Monotypic Caryophyllales genera Taxa described in 2020