''Bidens frondosa'' is a

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

n species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the aster family,

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

. It is widespread across much of

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

''Bidens frondosa''.
Flora of North America. It is known in many other parts of the world as an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

, including

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

, and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Its many common names include devil's beggarticks, devil's-pitchfork, devil's bootjack, sticktights, bur marigold, pitchfork weed, tickseed sunflower,''Bidens frondosa''.
Integrated Taxonomic Information System (ITIS). leafy beggarticks,''Bidens frondosa''.
Burke Museum. University of Washington. and common beggar-ticks.''Bidens frondosa''.
Freckmann Herbarium. University of Wisconsin, Stevens Point.

Habitat and range

''Bidens frondosa'' grows best where there is ample soil moisture and sun, especially in areas where something has disrupted the existing plant community leaving bare ground. It can survive in water saturated soils, frequently found growing at the water's edge, in drainage ditches or on flood plains. According to

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

(POWO) the natural range of ''Bidens frondosa'' is recorded as the whole of the continental United States except for Montana as well as all of Canada except for Labrador and the three Arctic territories. The USDA

Natural Resources Conservation Service Natural Resources Conservation Service (NRCS), formerly known as the Soil Conservation Service (SCS), is an agency of the United States Department of Agriculture (USDA) that provides technical assistance to farmers and other private landowners and ...

PLANTS database (PLANTS) agrees with the natural range in America, but lists it as an introduced plant for Canada. POWO lists the areas of the world where it is growing as an introduced plant as all of Europe except for Greece, Ireland, Iceland, Russia, Sweden, and Finland as well as Turkey, parts of Russia, China, Tadzhikistan, and the Caucasus.

Ecology

The defoliating

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

of '' Hadjina chinensis'', which is limited to ''Bidens'' species, has been observed on this plant.

Morphology

''Bidens frondosa'' is an annual herb, usually growing to tall, but it may reach . The stems are square in cross-section and may branch near the top. The leaves are

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

, divided into a few toothed triangular or lance-shaped leaflets usually long, exceptionally up to . The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is often a solitary flower head, but there may be pairs or arrays of several heads. The head contains many orange

disc floret Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

s. Most flower heads lack

ray florets Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger fa ...

but some may 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.Devils Beggarticks or Stick-tights: ''Bidens frondosa''.
Virginia Tech Weed Identification Guide. The barbed pappi on the fruit help it stick to animals, facilitating

seed dispersal In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

Invasive species

This plant is invasive in some parts of the world. In New Zealand it is classed as an environmental

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

by the Department of Conservation. It is also weedy in its native range, occurring in pastures and fields and along roadsides.

References

External links

CalPhotos photos gallery, University of California
{{Taxonbar, from=Q1560642 frondosa Flora of Northern America Plants described in 1753 Taxa named by Carl Linnaeus Invasive plant species in Japan