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black bindweed, climbing bindweed, climbing knotweed, Eurasian black bindweed, ivy bindweed

climbing false buckwheat, copse-bindweed, renouée des haies, thicket bindweed

Habit Herbs, annual, not rhizomatous, 0.5–1 m. Herbs, annual, not rhizomatous, to 3 m.
Stems

scandent or sprawling, branched proximally, herbaceous, puberulent, sometimes mealy, not glaucous.

scandent or climbing, rarely prostrate, freely branched, herbaceous, glabrous to papillose or scabrid, not glaucous.

Leaves

ocrea persistent or deciduous, tan or greenish brown, cylindric, 2–4 mm, margins oblique, face not fringed with reflexed hairs and slender bristles at base, otherwise glabrous or scabrid;

petiole 0.5–5 cm, puberulent in lines;

blade cordate-ovate, cordate-hastate, or sagittate, 2–6(–15) × 2–5(–10) cm, base cordate, margins wavy, scabrid, apex acuminate, abaxial face usually mealy and, rarely, minutely dotted, not glaucous, adaxial face glabrous.

ocrea usually deciduous, tan or brown, cylindric to funnelform, 1.5–3.5 mm, margins oblique, face not fringed with reflexed hairs and slender bristles at base, otherwise glabrous or scabrid;

petiole 0.3–2.5 cm, glabrous or scabrid in lines;

blade triangular to hastate, 2–8 × 1–5 cm, base cordate to truncate, margins wavy, scabrid, apex acute to acuminate, abaxially and adaxially faces glabrous or papillose to scabrid, not glaucous, the abaxial rarely minutely dotted.

Inflorescences

axillary, erect or spreading, spikelike, 2–10(–15) cm, axes puberulent;

peduncle 0.1–10 cm or absent, glabrous or scabrid distally in lines.

axillary, erect or spreading, racemelike, 2–20 cm, axes glabrous or scabrid;

peduncle 0.1–6 cm or absent, glabrous or scabrid.

Pedicels

ascending or spreading, articulated distally, 1–3 mm, glabrous or, rarely, scabrid.

ascending or spreading to deflexed, articulated distally, 4–8 mm, glabrous.

Flowers

bisexual, 3–6 per ocreate fascicle;

perianth nonaccrescent, greenish white, often with pinkish or purplish base, 3–5 mm including stipelike base, glabrous or outer 3 with blunt, hyaline hairs;

tepals elliptic to obovate, apex obtuse to acute, outer 3 obscurely keeled;

stamens 8;

filaments flattened proximally, glabrous;

styles connate distally;

stigmas capitate.

bisexual, 2–6 per ocreate fascicle;

perianth accrescent in fruit, greenish white or pinkish, 3.5–7 mm including stipelike base, glabrous;

tepals elliptic to obovate, apex obtuse to acute, outer 3 winged;

stamens 8;

filaments flattened proximally, pubescent proximally;

styles connate;

stigmas capitate.

Achenes

included, black, 4–5(–6) × 1.8–2.3 mm, dull, minutely granular-tuberculate, especially on faces; fruiting perianth glabrous or with blunt, hyaline hairs, wings absent or, rarely, flat to undulate, 0.4–0.9 mm wide at maturity, scarcely decurrent on stipelike base, margins entire.

included, black, 2–4 × 1.8–2.4 mm, shiny, smooth; fruiting perianth glabrous, wings flat or, less often, undulate or crinkled, 1.5–2 mm wide, usually truncate or attenuate-decurrent on stipelike base nearly to articulation, margins entire or rarely undulate-crenate.

2n

= 40.

= 20.

Fallopia convolvulus

Fallopia dumetorum

Phenology Flowering May–Oct. Flowering Jul–Oct.
Habitat Cultivated ground, waste places Hedges, wood borders, fields, waste ground
Elevation 0-2700 m (0-8900 ft) 0-300 m (0-1000 ft)
Distribution
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; YT; SPM; Greenland; Eurasia [Introduced in North America; introduced in South America (Argentina, Chile), Africa (Algeria, Morocco, Republic of South Africa), Pacific Islands (Hawaii, New Zealand), Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON; QC; Europe; Asia [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
Discussion

Fallopia convolvulus can be an aggressive weed in crop fields. Rare plants with winged fruiting perianths have been named var. subalata; that characteristic often varies within populations.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Because of similarity to Fallopia scandens, specimens of F. dumetorum often are misidentified. Consequently, the range of F. dumetorum in North America is unclear; it is probably exaggerated in most floras.

Mature fruiting perianths provide the most reliable characters distinguishing Fallopia dumetorum from F. scandens. European specimens of F. dumetorum, have fruiting perianths that are consistently orbiculate in outline, with wings usually flat and abruptly contracted on the stipelike perianth bases. Fallopia scandens has fruiting perianths that are obovate in outline, with wings undulate and gradually decurrent on the stipelike perianth bases. Additional characteristics reported to distinguish F. dumetorum from F. scandens are its annual habit (F. scandens also is reported to be annual in some of the literature) and more triangular leaf blades with cordate or sagittate bases. In recognizing F. dumetorum, we follow S. T. Kim et al. (2000) and M. H. Kim et al. (2000), who concluded from limited morphological and flavonoid data that the taxa are best treated as distinct species. More detailed studies may prove the two to be conspecific.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 545. FNA vol. 5, p. 546.
Parent taxa Polygonaceae > subfam. Polygonoideae > Fallopia Polygonaceae > subfam. Polygonoideae > Fallopia
Sibling taxa
F. baldschuanica, F. cilinodis, F. dumetorum, F. japonica, F. sachalinensis, F. scandens, F. ×bohemica
F. baldschuanica, F. cilinodis, F. convolvulus, F. japonica, F. sachalinensis, F. scandens, F. ×bohemica
Synonyms Polygonum convolvulus, Bilderdykia convolvulus, F. convolvulus var. subalata, Reynoutria convolvulus, Tiniaria convolvulus Polygonum dumetorum, Bilderdykia scandens var. dumetorum, Polygonum scandens var. dumetorum, Reynoutria scandens var. dumetorum, Tiniaria dumetorum
Name authority (Linnaeus) Á. Löve: Taxon 29: 300. (1970) (Linnaeus) Holub: Folia Geobot. Phytotax. 6: 176. (1971)
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