Polygonaceae

Taxonomy

Family name: Polygonaceae Jussieu

Synonym(s): Calligonaceae Khalk.; Coccolobaceae F. A. Barkley, nom. nud.; Eriogonaceae G. Don; Persicariaceae Martinov; Rumicaceae Martinov

Common name(s): buckwheat family

*Number of genera/species: 53/1,200

List of genera records in GRIN-Global

Disseminule

fruit

Description

Fruit usually an acheneachene:
a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point, derived from a single, superior, simple or compound, one-loculed ovary
, surrounded by fleshy or dry indehiscentindehiscent:
not opening on its own, as in a fruit
, often accrescentaccrescent:
growing continuously
perianth, rarely a samarasamara:
a winged, indehiscent, dry fruit containing a single (rarely two) seed(s)
(Afrobrunnichia, Brunnichia), 1–12 mm long, usually trigonoustrigonous:
3D shape—having three faces that meet at distinct angles; triangular in outline
, sometimes 2-angled (rarely 4), lens-shapedlens-shaped:
2D shape—round and flattened with two curved (convex) surfaces
, ovoidovoid:
3D shape—ovate
, or ellipsoidellipsoid:
3D shape—elliptic
, or rarely globoseglobose:
3D shape—more or less spherical
(Rheum spp.), coiledcoiled:
(of embryo) linear embryo is very long and bent to form a coil whereby one end of the embryo is on the outside and the other end near the middle of the seed
(Calligonum), reniformreniform:
2D or 3D shape—kidney-shaped
(Rheum nanum), usually 3-angled and tereteterete:
approximately circular in cross section; width and thickness approximately equal
or compressedcompressed:
flattened; in grasses, used to denote compression (not necessarily flattened) either laterally or dorsiventrally
in transection, stylestyle:
in a flower, the narrow and elongated part of the pistil between the stigma and the ovary; sometimes persisting in fruit
persistent, rarely beakedbeak:
a usually firm, terminal appendage, sometimes tapered
(Petrophyrum), pericarppericarp:
fruit wall or fruit coat
or perianthperianth:
collective term for calyx and corolla of a flower
winged, if winged, with three laterallateral:
(of embryo) embryo lies along the side of the seed, generally towards one end; of, at, or from the side; in grasses, can refer to the sides adjacent to the dorsal and ventral sides
wings, usually membranousmembranous:
texture—extremely thin, pliable, and fairly tough
, leatheryleathery:
texture—moderately thick, tough, and very pliable
, or hardened. Fruits with one seed, enclosed by fleshy floral tube (Coccoloba), fleshy tepalstepal:
a member of the perianth, when it cannot be differentiated into a calyx and corolla
(Muehlenbeckia, Symmeria), leatheryleathery:
texture—moderately thick, tough, and very pliable
expanded and flattened floral tube forming wings (Afrobrunnichia, Brunnichia), enlarged receptacle (Oxygonum, Rumex spp.), or dry, accrescentaccrescent:
growing continuously
perianth or calyxcalyx:
the outer whorl of the perianth; all the sepals of a flower
, which may develop into wings and/or harden into tubercles (Rumex spp.). Or, fruit with one seed and perianthperianth:
collective term for calyx and corolla of a flower
not enlarged in fruit (e.g. Polygonum). Pericarppericarp:
fruit wall or fruit coat
black, brown, gray, purple-red, red, or yellow, dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
, shinyshiny:
uniformly reflecting a high proportion of incident light at all angles
, or opaqueopaque:
not transmitting light
, crustaceouscrustaceous:
texture—thin, dry, indurate, and brittle
or thin, glabrousglabrous:
without hairs
or pubescentpubescent:
surface relief—bearing hairs
. Perianthperianth:
collective term for calyx and corolla of a flower
derived wings maybe different color than acheneachene:
a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point, derived from a single, superior, simple or compound, one-loculed ovary
. Surface relief, of pericarppericarp:
fruit wall or fruit coat
or more likely persistent perianthperianth:
collective term for calyx and corolla of a flower
, smooth or groovedgrooved:
surface relief—linear depressions that may be single or form a series of grooves over the surface
, ribbedribbed:
surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface
, pittedpitted:
surface relief—surface with small depressions in which the areas between the hollows do not take on the appearance of a true reticular net
, rough, granulargranular:
surface relief—having a grainy surface
, punctatepunctate:
surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted
, striatestriate:
surface relief—having fine, parallel lines, grooves or ridges
, prickly, wartywarty:
surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose
(Rumex), or with soft or stiff, forked or not bristles (Calligonum spp., Pteropyrum spp.), terminal stellatestellate:
star-shaped; with radiating branches
barbs (Fagopyrum snowdenii), or reflexed hornshorn:
a straight or curved, slenderly conic or conoidal protrusion, resembling an animal horn
(Rumex spp.).

Seeds globoseglobose:
3D shape—more or less spherical
to trigonoustrigonous:
3D shape—having three faces that meet at distinct angles; triangular in outline
, usually angledangular:
2D shape—having sides that meet at acute or obtuse angles  
, tereteterete:
approximately circular in cross section; width and thickness approximately equal
, lens-shapedlens-shaped:
2D shape—round and flattened with two curved (convex) surfaces
, or angledangular:
2D shape—having sides that meet at acute or obtuse angles  
in transection, 1–7 mm long. Margins, if winged. Seed coat black, brown, or red- or yellow-brown, dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
, glabrousglabrous:
without hairs
, smooth.

Embryo well developed, completely or partially filling seed coat, peripheralperipheral:
(of embryo) embryo is curved around the outer edge of the seed, near the seed coat
, axileaxile:
on or of the axis
and excentric, or rarely centric, linearlinear:
(shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide
, straight or often curvedcurved:
(of embryo) linear embryo is curved into an arch or horseshoe with the ends far apart
, usually lying in one of the angles of the seed. Cotyledons thin, foliaceous or not, flat, once-folded, or convoluted.

Endosperm copious, opaqueopaque:
not transmitting light
or transparent, fleshy, horny, mealymealy:
loose, dry, and disintegrating in finely granular pieces like meal or flour
, or granulargranular:
surface relief—having a grainy surface
, sometimes ruminateruminate:
testa or seed coat folded into the endosperm
.

Weed information

Many species of Polygonum are weedy and spreads by seed reproduction. It often forms dense clumps or predominant populations in suitable habitats.

Noxious Weeds: USA Federal Noxious Weed List, terrestrial, Rumex hypogaeus T.M. Schuster & Reveal (=*Emex australis Steinh.), Rumex spinosa L. (=*Emex spinosa (L.) Campdera).

*Name listed in USA Federal Noxious Weed Regulations and tool linked below.

Federal Noxious Weed Disseminules of the US tool provides descriptions and images of these species. Aquarium & Pond Plants of the World tool includes descriptions and images of genera, which may be encountered.

Identification features

Fruit
Type	acheneachene: a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point, derived from a single, superior, simple or compound, one-loculed ovary
Size range	1–12 mm long
Shape(s)	usually trigonoustrigonous: 3D shape—having three faces that meet at distinct angles; triangular in outline , also 2-angled (rarely 4), lens-shapedlens-shaped: 2D shape—round and flattened with two curved (convex) surfaces , globoseglobose: 3D shape—more or less spherical , ovoidovoid: 3D shape—ovate , ellipsoidellipsoid: 3D shape—elliptic , coiledcoiled: (of embryo) linear embryo is very long and bent to form a coil whereby one end of the embryo is on the outside and the other end near the middle of the seed , reniformreniform: 2D or 3D shape—kidney-shaped
Texture	crustaceouscrustaceous: texture—thin, dry, indurate, and brittle or thin
Surface relief	smooth, groovedgrooved: surface relief—linear depressions that may be single or form a series of grooves over the surface , ribbedribbed: surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface , pittedpitted: surface relief—surface with small depressions in which the areas between the hollows do not take on the appearance of a true reticular net , rough, granulargranular: surface relief—having a grainy surface , punctatepunctate: surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted , striatestriate: surface relief—having fine, parallel lines, grooves or ridges , prickly, wartywarty: surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose , with bristles, barbs, or reflexed hornshorn: a straight or curved, slenderly conic or conoidal protrusion, resembling an animal horn
Color(s)	black, brown, gray, purple-red, red, yellow
Unique features	Usually trigonoustrigonous: 3D shape—having three faces that meet at distinct angles; triangular in outline achenesachene: a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point, derived from a single, superior, simple or compound, one-loculed ovary often winged or enclosed by persistent, accrescentaccrescent: growing continuously , dry or fleshy perianthperianth: collective term for calyx and corolla of a flower , if dry maybe winged.
Seed
Size range	1–7 mm long
Shape(s)	trigonoustrigonous: 3D shape—having three faces that meet at distinct angles; triangular in outline , ovoidovoid: 3D shape—ovate , cordiformcordiform: 3D shape—heart-shaped , ellipsoidalellipsoid: 3D shape—elliptic , globoseglobose: 3D shape—more or less spherical
Surface relief	smooth
Color(s)	black, brown, red-brown, yellow-brown
Unique features	Dulldull: reflecting only a low proportion of incident light, with no apparent sheen brown or black, glabrousglabrous: without hairs , smooth seeds tightly adhered to pericarppericarp: fruit wall or fruit coat , with punctatepunctate: surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted hilahilum: on seeds, the scar indicating where the funiculus was attached; on grass caryopses, the scar visible on the outer fruit surface revealing where the seed is attached on the inner fruit wall surface; or in Asteraceae cypselae, the scar visible on the outer fruit wall revealing where the fruit was attached to the receptacle and copious endosperm.
Other
Embryo	well developed, completely or partially filling seed coat, peripheralperipheral: (of embryo) embryo is curved around the outer edge of the seed, near the seed coat , axileaxile: on or of the axis and excentric, or rarely centric, linearlinear: (shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide , straight or often curvedcurved: (of embryo) linear embryo is curved into an arch or horseshoe with the ends far apart , usually lying in one of the angles of the seed. Cotyledons thin, foliaceous or not, flat, once-folded, or convoluted.
Nutritive tissue	endosperm copious, opaqueopaque: not transmitting light or transparent, fleshy, horny, mealymealy: loose, dry, and disintegrating in finely granular pieces like meal or flour , or granulargranular: surface relief—having a grainy surface , sometimes ruminateruminate: testa or seed coat folded into the endosperm

Distribution

Worldwide, especially north temperate regions.

Distribution map courtesy of Angiosperm Phylogeny Website.

References

Cornejo and Janovec 2010Cornejo and Janovec 2010:
Cornejo F and Janovec J. 2010. Seeds of Amazonian Plants. Princeton University Press, Princeton and Oxford. ; Flora of Australia 2021+Flora of Australia 2021+:
Flora of Australia. Australian Biological Resources Study, Canberra. Accessed January 2021–March 2024. URL: http://www.ausflora.org.au; Flora of North America Editorial Committee 1993+Flora of North America Editorial Committee 1993+:
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. Flora of North America Association, New York and Oxford. Accessed January-March 2024. URL: http://beta.floranorthamerica.org.; Kirkbride et al. 2006Kirkbride et al. 2006:
Kirkbride JH, Jr, Gunn CR, and Dallwitz MJ. 2006. Family guide for fruits and seeds, vers. 1.0. Accessed September 2020-January 2022. URL: https://nt.ars-grin.gov/seedsfruits/keys/frsdfam/index.cfm .; Kubitzki et al. 1990+Kubitzki et al. 1990+:
Kubitzki K et al., eds. 1990+. The families and genera of vascular plants. 7+ vols. Berlin etc.; Noxious Weed Regulations 2020Noxious Weed Regulations 2020:
Noxious Weed Regulations. 2020. 7 C.F.R. sect; 360.100-360.600.; PlantNET 2021+PlantNET 2021+:
PlantNET (The NSW Plant Information Network System). 2021+. Royal Botanic Gardens and Domain Trust, Sydney. Accessed January 2021–March 2024. URL: https://plantnet.rbgsyd.nsw.gov.au; Takhtajan 2009Takhtajan 2009:
Takhtajan A. 2009. Flowering plants: Second edition. Springer Nature, Switzerland. 871 pp.; USDA 1980USDA 1980:
United States Dept. of Agriculture (USDA). 1980. Major weed family identification guide. Hyattsville Md, United States ; Zhengyi et al. 2004+Zhengyi et al. 2004+:
Zhengyi W, Raven PH, and Deyuan H. 2004+. Flora of China [online]. 25 vols. Science Press, Beijing China & Missouri Botanical Garden, St. Louis USA. Accessed January–March 2024. http://flora.huh.harvard.edu/china/

*The number of genera and species is based on Christenhusz and Byng 2016Christenhusz and Byng 2016:
Christenhusz MJM and Byng JW. 2016. The number of known plant species in the world and its annual increase. Phytotaxa 261 (3): 201-217. https://doi.org/10.11646/phytotaxa.261.3.1, which may differ from the number of genera in GRIN-Global.