Devil's beggarticks (Bidens frondosa, L. 1753)

Identité

Devil's beggarticks (Bidens frondosa L., 1753) is an accepted species of Bidens in the Asteraceae. POWO and IPNI attribute the name to Linnaeus in 1753 and place its native range in Canada and the contiguous United States. English aliases include devil's-pitchfork, devil's bootjack, leafy beggarticks, sticktights and bur marigold. ^{1 2}

Two barbed awns at the tip of each fruit explain the genus name Bidens, from Latin bi- (two) and dens (tooth). The epithet frondosa means leafy or bushy, describing the dense foliage of mature plants. ⁵

European populations became established around the start of the 20th century, and France now regards Bidens frondosa as an invasive alien species. Its spread and competition with native trifid bur-marigold (Bidens tripartita) matter more than any horticultural use. ^{3 9}

Recognition

An upright, angular, often reddish stem carries this annual to 30 cm–1.5 m (1–5 ft), depending on soil moisture. On sunny riverbanks, the plant quickly develops a bushy outline. ⁶

Opposite compound leaves comprise three to five sharply toothed, lance-shaped leaflets. Each distinct leaflet has its own scarcely winged stalklet. These nearly bare stalklets distinguish Bidens frondosa from Bidens tripartita, whose lobed leaves have clearly winged stalks rather than separate leaflets. ⁷

Discoid flower heads measure 1–2 cm (0.4–0.8 in) across. Most plants lack well-developed yellow-orange ray florets, so the flowers can be easy to overlook even on a 1.5 m (5 ft) stem. In France, flowering runs from August to October, corresponding to late summer and fall. ⁶

Useful taxonomy

Botanical names listed under Bidens frondosa L. by POWO include Bidens frondosa var. puberula Wiegand, var. major Hook., var. minor Hook., var. anomala Porter ex Fernald, var. caudata Sherff, var. pallida (Wiegand) Wiegand and var. stenodonta Fernald & H.St.John. These names belong to the same accepted taxon. ¹

Those botanical varieties are minor taxonomic ranks, useful for synonymy rather than garden selection. They do not represent horticultural breeding, and no ornamental cultivar is recorded for the species. ¹

Regional common names can differ sharply: French sources use bident feuillu, whereas Devil's beggarticks is an English name. The scientific name provides a consistent reference across languages and regional populations. ³

Habitat and range

Canada and the contiguous United States form the native temperate range recorded by POWO and WCVP. Waterlogged ground supports the species along rivers, ditches, floodplains, ponds and lakes. ^{1 5}

After its introduction to Europe in the early 20th century, the plant naturalized across much of the continent and subsequently in Asia and New Zealand. Invmed describes its French impact as major in the southwest and Massif Central, moderate in the Pyrenees and along the Mediterranean coast, with prevention the priority in Alpine areas. These are regional French assessments. ⁹

Dense stands compete directly with Bidens tripartita for wetland habitat. A single plant can produce up to 10,000 seeds, helping it colonize rapidly after flooding or disturbance of a riverbank. ⁹

Life cycle and reproduction

Seed is the only means of reproduction for this strictly annual species. Germination takes place on bare, moist ground in spring; flowering follows in late summer and fall, before frost kills the plant. The French flowering record is August through October. ^{9 6}

Flattened, dark brown to black fruits end in two barbed awns. Their barbs point forward in Bidens frondosa but backward in Bidens tripartita, a technical yet reliable distinction when leaves do not settle identification. ⁷

Hooked onto fur, feathers or clothing, the fruits disperse by epizoochory, transport on an animal's outer surface. Fruits that fall beside a watercourse can also float downstream, establishing new patches farther along the river. ⁵

Uses and risks

Cooked young shoots and leaves account for the main recorded food use. Their culinary value is considered minor, and a sweet aftertaste is sometimes reported. ^{8 5}

Traditional use for urinary irritation has also been recorded. Laboratory extracts show antibacterial and antioxidant properties, but these remain traditional practices or experimental findings, rather than established medical indications. ⁸

Human food toxicity is not documented, and common veterinary toxicity references provide no species profile. Missing animal data do not establish safety. The documented concerns are chiefly ecological competition with native vegetation and the mechanical nuisance of hooked fruits on fur, clothing and field equipment. ^{8 9}

Varieties, look-alikes and related plants

Garden varieties are absent: the botanical ranks listed by POWO serve scientific synonymy rather than plant selection. Identifying this wetland annual is more relevant than planting it. ¹

Trifid bur-marigold, Bidens tripartita, is the main look-alike in the same wet habitats. Its deeply lobed leaves have clearly winged stalks, unlike the separate leaflets on scarcely winged stalklets in Bidens frondosa. Fruit characters confirm identification when the leaves remain ambiguous. ⁷

Other Bidens species and young weeds on damp disturbed ground can look similar before flowering. Using Bidens frondosa as the reference name avoids confusion between French bident feuillu and American Devil's beggarticks, which name the same plant. ³

Main sources

• Plants of the World Online / Kew, Bidens frondosa L.
• International Plant Names Index, Bidens frondosa L.
• INPN / MNHN–OFB, Bidens frondosa L., CD_NOM 85957 — original notice, Internet Archive 2022-12-11
• USDA PLANTS Database, Bidens frondosa, devil's beggarticks (BIFR)
• Tela Botanica, Jacques Jacqva, Le Bident feuillu (20 October 2022), original article archived 7 October 2024
• FloreAlpes, Bidens frondosa - leafy beggarticks
• FloreAlpes, comparison of Bidens frondosa and Bidens tripartita
• Plants For A Future, Bidens frondosa — Internet Archive, 2026-06-06
• Invmed / invasive alien species observatory, Bidens frondosa profile