Bidens melanocarpa Wiegand
Bidens frondosa is a North American species of flowering plant in the aster family, sunflower family. It is widespread across much of Canada, the United States, and Mexico It is known in many other parts of the world as an introduced species, including Europe, Asia, Morocco, and New Zealand. Its many common names include devil's beggarticks, devil's-pitchfork, devil's bootjack, sticktights, bur marigold, pitchfork weed, tickseed sunflower, leafy beggarticks, and common beggar-ticks.
Bidens frondosa is annual herb is usually about 20 to 60 (8-20 inches) centimeters tall, but it can reach 1.8 meters (72 inches or 6 feet) at times. The stems are square in cross-section and may branch near the top. The leaves are pinnate, divided into a few toothed triangular or lance-shaped leaflets usually up to 6 or 8 centimeters long, sometimes up to 12. The inflorescence is often a solitary flower head, but there may be pairs or arrays of several heads. The head contains many orange disc florets. It often lacks ray florets but some heads have a few small yellow rays. The fruit is a flat black or brown barbed cypsela up to a centimeter long which has two obvious hornlike pappi at one end.
This plant is invasive in some parts of the world. In New Zealand it is classed as an environmental weed by the Department of Conservation. It is also weedy in its native range, occurring in pastures and fields and along roadsides.
- The Plant List, Bidens frondosa L.
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- Bidens frondosa. Flora of North America.
- Biota of North America Program 2014 state-level distribution map
- Flora of China, 大狼杷草 da lang pa cao, Bidens frondosa Linnaeus, Sp. Pl. 2: 832. 1753.
- Altervista Flora Italiana, Forbicina fogliosa, schwarzfrüchtiger Zweizahn, Bidens frondosa L.
- Bidens frondosa. Integrated Taxonomic Information System (ITIS).
- Bidens frondosa. Burke Museum. University of Washington.
- Bidens frondosa. Freckmann Herbarium. University of Wisconsin, Stevens Point.
- Devils Beggarticks or Stick-tights: Bidens frondosa. Virginia Tech Weed Identification Guide.
- Bidens frondosa. The Jepson eFlora 2013.
- Han, Y. G., et al. (2009). Insect herbivores associated with the introduced weed Bidens frondosa L.(Asteraceae) in Korea, and their potential role as augmentative biological control agents. Entomological Research 39(6), 394-400.
- Howell, C. (May 2008). Consolidated List of Environmental Weeds in New Zealand. 292. Wellington, New Zealand: Department of Conservation. ISBN 978-0-478-14413-0.
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