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Clintonia, Volume 30, Issue 4, December 2015
The Invasive Species Cardamine hirsuta L. (Hairy Bittercress) at DeVeaux Woods _S tate Park,
Western New York State
P.M. Eckel, Missouri Botanical Garden, P.O. Box 299, St. Louis; M0.63166 ·.
The genus Cardamine (Brassicaceae) in the Niagara Frontier Region has been represented by 10 species (Eckel 2012). The
discovery of Cardamine hirsuta provides an eleventh.
Cardamine hirsuta was not reported for the Niagara Frontier Region by Charles Zenkert in 1934 and was first mentioned
for the Region by Zander and Pierce (1979) who listed it as a rare introduction and excluded it. Eaton and Schrot (1987) did
not report it for the flora of Cattaraugus County.
The species, as described by Linnaeus (Species Plantarum Vol. 2: p. 655. 1753,) was not reported for New York State by
Homer House (1924). House noted that the report of Cardamine hirsuta in John Torrey's New York State Flora (1843) was
actually Cardamine pensylvanica Muhl. ex Willd., a species that is now known to occur throughout the State (Weldy, et al.,
2015).
In Canada, Province of Ontario, the Regional Municipality of Niagara' comprises;}lluch gf the Niagara Frontier Region
(which is an area with a radius of fifty miles from a point near the center of the City ofBuf(alo, NY). Oldham (2010) noted
Cardamine hirsuta as an uncommon introduction "known from fl to 20 recently verified (post 1980) locations in the
Niagara Regional Municipality;" another indicator (SE3) reports 21-80 ~ites. By the Niagara River, Oldham found a
specimen, described as "an uncommon weed of open disturbed areas. Small and early flowering, therefore easily
overlooked. M.J. Oldham #32347 (TRT) from Niagara Parkway south of Niagara-on-the-Lake in 2006" (Oldham 20 10).
In 1979, when Zander and Pierce noted the occurrence of this plant in the Niagara Region, they considered it to be rare and
not persisting. There is much evidence that this species may be uncommon in the Region, but it will probably not remain
so.
In New York State, the species is listed as "common," but with a scattered distribution throughout the State (Weldy, et al.,
2015).
.
Specimen citation:
Cardamine hirsuta L. USA. New York. Niagara Co., City of Niagara Falls, DeVeaux Woods State Park. One of a
population of invasive species in moist shaded woods of native trees, associated with light wells where the canopy
has opened, with Arctium minor, Solanum dulcamara, Ranunculus fica ria and other weeds, separate from the suite
of native species, Polygonatum, Smilacina. Coil. P.M. Eckel, May 12, 2014 (MO).
Cardamine hirsuta is an introduced species with a broad global amplitude: occurring naturally "Throughout China [India,
Indonesia, Japan, Laos, Malaysia, New Guinea, Pakistan, Philippines, Sikkim, Sri Lanka, Thailand, 'J'urkmenistan,
Vietnam; SW Asia, Europe; naturalized inS Africa, Australia, North and South America]'(Flora of China Vol. 8, p. 104).
The species occurs as an introduction throughout North America except three states ·in New England and in central north
America and Canada in the plains states, and New Mexico and Arizona (Flora ofNorth-ArrieticaV<il. 7}.~
As noted above, the species is perhaps often overlooked as it is a small plant with tiriy white flbw~rs, fl~wering from eatly ·
spring through to autumn. As a winter annual, being green throughout the winter months, it may be· sought as a' basal
rosette. The station at DeVeaux Woods State Park most likely derived from the masses ·of nurseryj garden -center. and
contractor soil from excavations, plantations and foreign soil deposits throughout the parks system along the Niagara, River,
as it is "often introduced unwittingly on the compost of container plants" and "as with all annual weeds it is essential to
destroy it before seed can be produced" (RHS viewed 2015). At one time the species may have not survived in the Niagara
Region, but it is now understood as difficult to eradicate once established.
If the winter basal rosette is found one can always pluck it and contribute it to a salad raw as a garnish, where it is said to
yield a "hot cress-like flavor." The seed pods (siliques) are numerous, erect, and when touched when dry, can expel seeds
up to six feet (Marble, et a!. 20 14). The species, once established, is difficult to control due to "number of seeds.produced
as well as its fast germination and growth throughout the year." The species "commonly grows in the potting media of
container-grown ornamentals." Control in non-crop areas is "by mowing (when seeds are not present), and using densely
growing groundcovers or a gravel layer to improve drainage and reduce germination" (Marble, eta!. 2014) although it is
hoped the station in a State Park important for its native flora will not have to resort to these controls.
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Clintonia, Volume 30, Issue 4, December 2015
A problem in all of Niagara' s parks is that there is no one with professional expertise appointed to monitor and protect the
native ecological communities from the incursion of alien species.
LITERATURE CITED
Eaton, Steven W. & Edith Feuerstein Schrot. 1987. A Flora of the Vascular Plants of Cattaraugus County, New York. Bull.
Buffalo Soc. Nat. Sci. 31. Buffalo, New York.
Eckel, P.M. 2012. MADCapHorse II, A Second Revision of the Checklist and Nomenclatural Guide to the Vascular Flora
of the Niagara Frontier Region: Flora of the Niagara Frontier Region, Third Supplement. .
http://www.mobot.org/plantscienceiresbot/Fior/Madcap/lndex.htm
House, Homer H. 1924. Annotated list of the Ferns and Flowering Plants ofNew York State. New York State Museum
Bulletin no. 254, Albany, New York.
Marble, Chris, Shawn Steed, and Nathan S. Boyd. 2014. Biology and Management of Hairy Bittercress (Cardamine
hirsuta) in Ornamental Crop Production. Publication #ENH12501 the Environmental Horticulture Department,
UF/IFAS Extension.
Oldham, Michael J. 2010 (March). Checklist of the Vascular Plants ofNiagara Regional Municipality Ontario. Michael J.
Oldham, Ontario Natural Heritage Information Centre, Ministry of Natural Resources, Peterborough, Ontario for
Niagara Peninsula Conservation Authority Weiland, Ontario.
{RHS) Royal Horticultural Society. Bittercress. Website: viewed Nov. 1, 2015.
https://www.rhs.org.uk/advice/profile?PID=782
Torrey, J. 1843. A Flora of the State of New York, comj11ising full descriptions of all the indigenous and naturalized plants
hitherto discovered in the state; with remarks on their economical and medicinal properties. Vols. 1 & 2 ofNatural
History of New York. Albany.
Weldy, Troy, David Werier, and Andrew Nelson. 2015 New York Flora Atlas. New York Flora Association. Albany, New
York.
Zander, Richard H. & Gary J. Pierce. 1979. Flora of the Niagara Frontier Region. Second Supplement and Checklist. Bull.
Buffalo Soc. of Nat. Sci. 16. Buffalo, New York.
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Zenkert, Charles A. 1934. Flora of the Niagara Frontier Region. Bull. Buffalo Soc. Nat. Sci. 16. Buffalo, New York.