Monotypic Polygonaceae genera

Centrostegia is a monotypic genus of plants in the family Polygonaceae. Its sole species is Centrostegia thurberi, known by the common names '''Thurber's spineflower and red triangles'''. It is a petite herb with a distinct red coloration native to the southwestern United States and northwestern Mexico.

Gilmania luteola (called golden carpet or goldencarpet) is a rare annual plant in the Buckwheat family (Polygonaceae).

Leptogonum is a monotypic genus of plants in the family Polygonaceae. It has a single species, Leptogonum domingense, a shrub or tree endemic to the island of Hispaniola.

Pterostegia is a monotypic plant genus containing only the single species Pterostegia drymarioides, which is known as the woodland threadstem, woodland pterostegia, fairy mist, or fairy bowties.

Magoniella is a monotypic genus of flowering plants belonging to the family Polygonaceae. The only species is Magoniella obidensis. Its native range is Costa Rica, Venezuela to Brazil and Bolivia.

Systenotheca is a monotypic plant genus in the buckwheat family containing the single species Systenotheca vortriedei, which is known by the common name '''Vortriede's spineflower'''.

Dodecahema is a genus of plants in the family Polygonaceae with a single species restricted to California, where it is an endangered species on the state and federal levels. Its common name is slender-horned spineflower. This is a small annual plant forming a patch of spreading basal leaves a few centimeters in diameter, or slightly larger when more moisture is available. It bolts an erect stalk upon which it bears inflorescences of flowers. Each group of white or pink flowers is enclosed in a tiny cup of fused bracts which is only a few millimeters wide. The fruit is a dark achene about 2 mil

Aristocapsa is a genus of plants in the family Polygonaceae with a single species, Aristocapsa insignis, restricted to California. It is known by the common names Indian Valley spineflower or Indian Valley spinecape, and it is endemic to the inland southern Coast Ranges of Monterey and San Luis Obispo Counties.

The monotypic genus Dedeckera contains the single species Dedeckera eurekensis, a plant known by the common name July gold which is endemic to California. It is found in the mountains east and south of the Sierra Nevada, especially the Inyo and White Mountains.

Goodmania is a genus of plants in the family Polygonaceae containing the single species Goodmania luteola. Its common name is yellow spinecape. It is a tiny annual herb forming small patches on the ground no more than a few centimeters high and wide. It has fuzzy club-shaped leaves and bears bright yellow flowers. The plant is native to California and Nevada.

Nemacaulis is a monotypic plant genus in the buckwheat family containing the single species Nemacaulis denudata, which is known by the common names woollyheads and cottonheads. This plant is a somewhat undistinguished delicate annual herb with thin, spindly, naked stems and woolly white flowerheads. It can be found in sandy habitats in California, Arizona, and northern Mexico.

Brunnichia is a genus of flowering plants in the family Polygonaceae. It includes a single species, Brunnichia ovata, commonly known as redvine, American buckwheat vine or '''ladies' eardrops''', a woody vine native to the central and southeastern United States.

Hollisteria is a genus of plants in the family Polygonaceae with a single species, Hollisteria lanata. It is endemic to California. It is known by the common name false spikeflower.

Acanthoscyphus is a monotypic genus in the family Polygonaceae that contains the single species Acanthoscyphus parishii, which is sometimes called '''Parish's oxytheca'''. This species is native and endemic to southern California.