Polygonaceae in the context of Coccoloba

Buckwheat (Fagopyrum esculentum) or common buckwheat is a flowering plant in the knotweed family Polygonaceae cultivated for its grain-like seeds and as a cover crop. Buckwheat cultivation originated around the 6th millennium BC in the region of what is now Yunnan Province in southwestern China. The name "buckwheat" is used for several other species, such as Fagopyrum tataricum, a domesticated food plant raised in Asia.

Despite its name, buckwheat is not closely related to wheat, nor is it a cereal or a member of the grass family. It is related to sorrel, knotweed, and rhubarb. Buckwheat is considered a pseudocereal because the high starch content of the seeds enables buckwheat to be cooked and consumed like a cereal.

Polygonum is a genus of about 130 species of flowering plants in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In the Middle English glossary of herbs Alphita (c. 1400–1425), it was known as ars-smerte. There have been various opinions about how broadly the genus should be defined. For example, buckwheat (Fagopyrum esculentum) has sometimes been included in the genus as Polygonum fagopyrum. Former genera such as Polygonella have been subsumed into Polygonum; other genera have been split off.

The genus primarily grows in northern temperate regions. The species are very diverse, ranging from prostrate herbaceous annual plants to erect herbaceous perennial plants.

The docks and sorrels, genus Rumex, are a genus of about 200 species of annual, biennial, and perennial herbs in the buckwheat family, Polygonaceae.Members of this genus are very common perennial herbs with a native almost worldwide distribution, and introduced species growing in the few places where the genus is not native.

Some are nuisance weeds (and are sometimes called dockweed or dock weed), but some are grown for their edible leaves. Rumex species are used as food plants by the larvae of a number of Lepidoptera species, and are the only host plants of Lycaena dispar and Lycaena rubidus.

Fagopyrum tataricum, also known as Tartary buckwheat, green buckwheat, ku qiao, Tatar buckwheat, or bitter buckwheat, is a domesticated food plant in the genus Fagopyrum in the family Polygonaceae. With another species in the same genus, common buckwheat, it is often counted as a cereal, but the buckwheats are not closely related to true cereals.

Tartary buckwheat is more bitter and contains more rutin than common buckwheat. It also contains other bioactive components such as flavonoids, phenolic acids, 2-hydroxybenzylamine and quercitrin.

Sorrel (Rumex acetosa), also called common sorrel or garden sorrel, is a perennial herbaceous plant in the family Polygonaceae. Other names for sorrel include spinach dock and narrow-leaved dock ("dock" being a common name for the genus Rumex).

Sorrel is native to Eurasia and a common plant in grassland habitats. It is often cultivated as a leaf vegetable or herb.

Rhubarb is the fleshy, edible stalks (petioles) of species and hybrids (culinary rhubarb) of Rheum in the family Polygonaceae, which are cooked and used for food. The plant is a herbaceous perennial that grows from short, thick rhizomes. Historically, different plants have been called "rhubarb" in English. The large, triangular leaves contain high levels of oxalic acid and anthrone glycosides, making them poisonous and therefore inedible. The small flowers are grouped in large compound leafy greenish-white to rose-red inflorescences.

The precise origin of culinary rhubarb is unknown. The species Rheum rhabarbarum (syn. R. undulatum) and R. rhaponticum were grown in Europe before the 18th century and used for medicinal purposes. By the early 18th century, these two species and a possible hybrid of unknown origin, R. × hybridum, were grown as vegetable crops in England and Scandinavia. They readily hybridize, and culinary rhubarb was developed by selecting open-pollinated seed, so its precise origin is almost impossible to determine. In appearance, samples of culinary rhubarb vary on a continuum between R. rhaponticum and R. rhabarbarum. However, modern rhubarb cultivars are tetraploids with 2n = 44, in contrast to 2n = 22 for the wild species.

Caryophyllaceae, commonly called the pink family or carnation family, is a family of flowering plants. It is included in the eudicot order Caryophyllales in the APG III system, alongside 33 other families, including Amaranthaceae, Cactaceae, and Polygonaceae. It is a large family, with 105 genera and about 2,625 known species.

This cosmopolitan family of mostly herbaceous plants is best represented in temperate climates, with a few species growing on tropical mountains. Some of the more commonly known members include pinks and carnations (Dianthus), and firepink and campions (Silene). Many species are grown as ornamental plants, and some species are widespread weeds. Most species grow in the Mediterranean and bordering regions of Europe and Asia. The number of genera and species in the Southern Hemisphere is rather small, although the family does contain Antarctic pearlwort (Colobanthus quitensis), the world's southernmost dicot, which is one of only two flowering plants found in Antarctica.

Reynoutria japonica, synonyms Fallopia japonica and Polygonum cuspidatum, is a species of herbaceous perennial plant in the knotweed and buckwheat family Polygonaceae. Common names include Japanese knotweed and Asian knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats; it is classified as a pest and invasive species in several countries. The plant is popular with beekeepers and its young stems are edible, making it an increasingly popular foraged vegetable with a flavour described as lemony rhubarb.

Eriogonum is a genus of flowering plants in the family Polygonaceae. The genus is found in North America and is known as wild buckwheat. This is a highly species-rich genus, and indications are that active speciation is continuing. It includes some common wildflowers, such as the California buckwheat (Eriogonum fasciculatum).

The genus derived its name from the Greek word erion meaning 'wool' and gonu meaning 'knee or joint'. The author of the genus, Michaux, explained the name as describing the first named species of the genus (E. tomentosum) as a wooly plant with sharply bent stems ("planta lanata, geniculata"). Despite sharing the common name "buckwheat", Eriogonum is part of a different genus from the cultivated European buckwheat and than other plant species also called wild buckwheat.

Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds. It has a cosmopolitan distribution, with species occurring nearly worldwide. The genus was segregated from Polygonum.

Calligonum is a genus of plants in the family Polygonaceae with about 41 species native to Northern Africa, Western, South, and Central Asia, and central China.

The genus Fagopyrum is in the flowering plant family Polygonaceae. It includes some important food plants, such as F. esculentum (buckwheat) and F. tataricum (Tartary buckwheat). The genus is native to the Indian subcontinent, much of Indochina, central and southeastern China, and central and eastern tropical Africa. Species have been widely introduced elsewhere, throughout the Holarctic and parts of Africa and South America.

Rheum is a genus of about 60 herbaceous perennial plants in the family Polygonaceae. Species are native to eastern Europe, southern and eastern temperate Asia, with a few reaching into northern tropical Asia. Rheum species are cultivated in Europe, Asia, and North America. The genus includes the vegetable rhubarb. The species have large somewhat triangular shaped leaves with long, fleshy petioles. The flowers are small, greenish-white to rose-red, and grouped in large compound leafy inflorescences. Many rhubarb cultivars have been domesticated as medicinal plants and for human consumption. While the leaves are slightly toxic, the stalks are used in pies and other foods for their tart flavour.

Rheum rhabarbarum is a species of flowering plant in the family Polygonaceae, native to a region stretching from southern Siberia to north and central China. It has been harvested from the wild for centuries for its root, which was harvested for use as a popular medicine in Europe and Asia. It was later cultivated for its root in England and Russia. It is considered to be one of the species involved in the development of culinary rhubarb, for which the scientific name R. rhabarbarum is sometimes (erroneously) used.