''Bidens laevis'' is a species of flowering plant in the

daisy family 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 fam ...

known by the common names larger bur-marigold and smooth beggarticks. It is native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

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 ...

, and the southern and eastern

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 ...

. It grows in

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s, including

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

and riverbanks.Flora of North America, ''Bidens laevis'' (Linnaeus) Britton, Sterns & Poggenburg, Prelim. Cat. 29. 1888
/ref>Zuloaga, F. O., O. Morrone, M. J. Belgrano, C. Marticorena & E. Marchesi. (eds.) 2008. Catálogo de las plantas vasculares del Cono Sur. Monographs in Systematic Botany from the Missouri Botanical Garden 107(1–3): i–xcvi, 1–3348. ''Bidens laevis'' is similar in appearance to its relative ''

Bidens cernua ''Bidens cernua'' is a species of flowering plant in the aster family, Asteraceae. ''Bidens cernua'' is distributed throughout much of Eurasia and North America.

'' and the two are sometimes confused. This is an annual or perennial herb growing over 20 centimeters tall and sometimes much taller, exceeding one meter in height and sometimes approaching two. The narrow lance-shaped leaves are 5 to 15 centimeters long, with finely toothed edges and pointed tips. 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 ...

bears one or more

flower heads A pseudanthium (; : pseudanthia) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers ...

which bend down as they become heavy with fruit after flowering. Each head has a center of yellow

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 and a fringe of 7 or 8 yellow

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 ...

each up to 3 centimeters long. The fruit is a dry

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

with sharp barbs that adhere to fur and clothing, thus helping the plant with seed dispersal.

References

External links

Jepson Manual TreatmentCalphotos Photo gallery, University of CaliforniaGo Botany, New England Wildflower Society, ''Bidens laevis'' (L.) B.S.P. , smooth beggar-ticksAtlas of Florida Vascular Plants
photos, United States Department of the Interior, National Park Service

* photo by Pablo J. Saubot {{Taxonbar, from=Q2901718 laevis Flora of Northern America Flora of Southern America Plants described in 1753 Taxa named by Carl Linnaeus