Summary

Did you know?

What has been called Bidens laevis along the Hudson River may in fact be a variation of another species since the characters of these plants do not quite match those of the typical Bidens laevis. More work is needed on identification of these specimens. Specimens from wetlands in the rest of the state are a good match for this plant. The species name laevis refers to the smooth stems.

State Ranking Justification

There are ten existing populations along the Hudson River and one in western New York. Historical records on Long Island are probably extirpated and the ten or so historical records from Central and Western New York have not been surveyed in detail and may still be extant.

Short-term Trends

Two of the existing 11 populations have been revisited since their original discovery. One population increased by hundreds of plants and the other population decreased by hundreds of plants. This may suggest that in the short-term populations may fluctuate greatly or that survey methods have not been consistent enough to measure plant population changes. Until more survey work is done and the identification and plant taxonomy issues are settled short-term trends will remain unknown.

Long-term Trends

The long-term trend of this species in New York is difficult to assess because plants in the marshes of central and western New York as well as Long Island may be different from the plants in the marshes of the Hudson River that have all been called Bidens laevis. The historical records from Long Island are from areas that have been highly developed and probably no longer exist. Some historical records from Hudson River marshes have been rediscovered and new populations also have been found. This area has probably seen a large fluctuation in the number of populations over the last 100 years but they seem to be doing fairly well recently. There has not been a recent targeted work to rediscover historical populations in the marshes of Central and Western New York so long-term trends here are unknown. In general marsh land has decreased in this area of the state and so may have these populations.

Conservation and Management

Threats

Habitat conversion has severely threatened historical records on Long Island and the Lower Hudson area and phragmites threatens some of the populations in the Hudson River tidal marshes. It is unknown what threatens populations in Central and Western New York if these populations still exist.

Conservation Strategies and Management Practices

Hudson River sites should be protected from overuse by recreational boaters and by invasion of phragmites.

Research Needs

Identification and taxonomic studies need to be done to find out if Long Island and Hudson River plants are different from Central and Western New York plants. Results will have a major impact on the protection of the species.

Habitat

Habitat

In New York this species is found primarily in freshwater and brackish tidal mud flats and tidal marshes, growing with Schoenoplectus americana, Zizania aquatica, Bidens bidentoides, Bidens cernua, Pontederia cordata, and Peltandra virginica. Historically, it was also collected inland in Western New York in swamps, marshy meadows and along streams. It is known from inland sites elsewhere in its range (New York Natural Heritage Program 2007). Marshes and margins of pools and sluggish streams, either fresh or brackish (Fernald 1970). Low wet places, sometimes in shallow water, estuaries (Gleason 1952).

Associated Ecological Communities

• Brackish intertidal mudflats (guide)
  A sparsely vegetated community, characterized by low-growing, rosette-leaved aquatics. The community occurs on exposed intertidal mudflats where water salinity ranges from 0.5 to 18.0 ppt. This community is best developed where mudflats are nearly level so that broad expanses are exposed at low tide. The rosette-leaved aquatics are completely submerged at high tide, and they are usually coated with mud.
• Brackish intertidal shore
  A community of the intertidal gravelly or rocky shores of brackish tidal rivers and creeks where water salinity ranges from 0.5 to 18.0 ppt.
• Brackish tidal marsh (guide)
  A marsh community that occurs where water salinity ranges from 0.5 to 18.0 ppt, and water is less than 2 m (6 ft) deep at high tide. The vegetation in a brackish tidal marsh is dense and dominated by tall grass-like plants.
• Freshwater intertidal mudflats (guide)
  A sparsely vegetated community characterized by low rosette-leaved aquatics. This community occurs on exposed intertidal mudflats where the water is fresh (salinity less than 0.5 ppt). This community is best developed where mudflats are nearly level so that broad expanses are exposed at low tide. The plants are completely submerged in 0.9 to 1.2 m (3 to 4 ft) of water at high tide and they are usually coated with mud.
• Freshwater tidal marsh (guide)
  A marsh community that occurs in shallow bays, shoals, and at the mouth of tributaries of large tidal river systems, where the water is usually fresh (salinity less than 0.5 ppt), and less than 2 m (6 ft) deep at high tide. Typically there are two zones in a freshwater tidal marsh: a low-elevation area dominated by short, broadleaf emergents bordering mudflats or open water, and a slightly higher-elevation area dominated by tall grass-like plants.
• Shallow emergent marsh (guide)
  A marsh meadow community that occurs on soils that are permanently saturated and seasonally flooded. This marsh is better drained than a deep emergent marsh; water depths may range from 6 in to 3.3 ft (15 cm to 1 m) during flood stages, but the water level usually drops by mid to late summer and the soil is exposed during an average year.

Associated Species

• Bidens bidentoides (estuary beggar-ticks)
• Bidens cernua (nodding beggar-ticks)
• Bolboschoenus
• Cinna arundinacea (stout wood-reed)
• Echinochloa
• Impatiens capensis (spotted jewelweed, spotted touch-me-not)
• Lobelia cardinalis (cardinal flower)
• Nuphar
• Peltandra virginica (green arrow-arum, tuckahoe)
• Persicaria punctata (dotted smartweed)
• Pontederia cordata (pickerelweed)
• Schoenoplectus americanus (chair-maker's bulrush)
• Zizania aquatica

Range

New York State Distribution

This species occurs on Long Island and along the Hudson River, and at scattered locations throughout much of the state, but not in Northern New York.

Global Distribution

This species occurs only in the United States, including most states east of the Mississippi, extending through the lower Mississippi Valley west to include include Texas, the Southwest, and California.

Identification Comments

General Description

Smooth Bur-marigold is an annual, opposite-leaved herb. It has sessile leaves, and is entirely glabrous. The flower-like heads are actually composed of many disc and ray flowers, the petal-like rays being yellow and about 1.5 to 3 cm long. The receptacular bracts (the chaff) are tipped with red. The disk flowers' corollas are mostly 5-lobed.

Best Life Stage for Proper Identification

Flowering plants, preferably with portions in fruit as well, are best for positive identification.

Similar Species

Bidens cernua has a stem that is soft and usually hairy. The outer involucre is longer than the inner, and the chaff is yellow-tipped. Bidens bidentoides and B. hyperborea var. hyperborea both have petiolate leaves, lack ray flowers, and have 4-lobed disc flower corollas.

Best Time to See

Smooth Bur-marigold flowers from mid-August through September, the fruits persist into October.

Smooth Beggar Ticks Images

Bidens laevis
Stephen M. Young

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Taxonomy

Smooth Beggar Ticks
Bidens laevis (L.) B.S.P.

• Kingdom Plantae
  • Phylum Anthophyta
    • Class Dicotyledoneae (Dicots)
      • Order Asterales
        • Family Asteraceae (Aster Family)

Additional Common Names

• Beggar-ticks
• Smooth Beggar-ticks

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2006. Flora of North America North of Mexico. Vol. 21. Magnoliophyta: Asteridae, Part 8: Asteraceae, part 3. Oxford Univ. Press, New York. xxii + 616 pp.

Other References

Clemants, Steven and Carol Gracie. 2006. Wildflowers in the Field and Forest. A Field Guide to the Northeastern United States. Oxford University Press, New York, NY. 445 pp.

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2023. New York Natural Heritage Program Databases. Albany, NY.

Newcomb, Lawrence. 1977. Newcomb's Wildflower Guide: An Ingenious New Key System for Quick, Positive Field Identification of the Wildflowers, Flowering Shrubs, and Vines of Northeastern and North-Central North America. Little, Brown and Company. Boston.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, Albany, New York

Weldy, Troy W. and David Werier. 2005. New York Flora Atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research. University of South Florida]. New York Flora Association, Albany, NY. Available on the web at (http://newyork.plantatlas.usf.edu/).

Links

• Google Images
• NatureServer Explorer
• New York Flora Atlas
• USDA Plants Database

About This Guide

Information for this guide was last updated on: January 13, 2009

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Bidens laevis. Available from: https://guides.nynhp.org/smooth-beggar-ticks/. Accessed October 3, 2023.