Fallopia convolvulus, the black-bindweed or wild buckwheat, is a fast-growing annual flowering plant in the family Polygonaceae native throughout Europe, Asia and northern Africa.[1] [2] [3] [4]
Synonyms include Polygonum convolvulus L. (basionym), Bilderdykia convolvulus (L.) Dumort, Fagopyrum convolvulus (L.) H.Gross, Fagopyrum carinatum Moench, Helxine convolvulus (L.) Raf., Reynoutria convolvulus (L.) Shinners, and Tiniaria convolvulus (L.) Webb & Moq.[2] [3] Other old folk names include bear-bind, bind-corn, climbing bindweed, climbing buckwheat, corn-bind, corn bindweed, devil's tether, and wild buckwheat.
Black-bindweed is a herbaceous vine growing to 1– long, with stems that twine clockwise round other plant stems. The alternate triangular leaves are 1.5–6 cm long and 0.7–3 cm broad with a 6–15 (–50) mm petiole; the basal lobes of the leaves are pointed at the petiole. The flowers are small, and greenish-pink to greenish white, clustered on short racemes. These clusters give way to small triangular achenes, with one seed in each achene.[1] [2] [3] [5] The flowers have 5 sepals, the 3 outer ones are larger and show a keel. It has 5 stamens and the fruit grows to 4 mm long.[6]
While it superficially resemble bindweeds in the genus Convolvulus there are many notable differences; it has ocrea (stipule-sheath at nodes), which Convolvulus does not; and Convolvulus has conspicuous trumpet-shaped flowers while Black-bindweed has flowers that are unobtrusive and only about 4 mm long.[4]
Fallopia convolvulus grows most commonly on disturbed or cultivated land, in northern Europe typically on warm, sunny, well-drained sandy or limestone soil types,[4] [5] but in hotter, drier areas like Pakistan, on moist shady sites.[3] It ranges from sea level in the north of its range, up to 3600 m altitude in the south in the Himalaya.[2] [3] [4]
The seeds are edible, and were used in the past as a food crop, with remains found in Bronze Age middens.[4] The seeds are too small and low-yielding to make a commercial crop, and it is now more widely considered a weed, occurring in crops, waste areas and roadsides. It can be a damaging weed when it is growing in a garden or crop, as it can not only damage the plants around which it twines, but also clog the machinery used to harvest a given crop. It is also an invasive species in North America.