The Long Island Invasive Species Management Area

Species Alerts

Early Detection Species - Be on the lookout! surprise

These are in low abundance and are managed for eradication in LIISMA

CLICK HERE to see their status in New York in the lists of early detection species


Hardy Kiwi (Actinidia arguta)

Look for this woody vine with flaky bark in secondary to mature deciduous woodlands

More research is needed to establish its invasive nature.

Important Links

Penn State Extension study results on invasiveness

Go Botany fact sheet

Identification key in the Flora of China

Cornell University fruit page

Google Images


Asiatic Sand Sedge (Carex kobomugi)

Look for this on sand dunes on the south shore of Long Island and Staten Island.

Important Links

Plant Conservation Alliance information

Dr. Louise Wooten studies of Carex kobomugi effects

Poster on chemical control efforts

Recognizing the look-alike Carex macrocephala

Ten years of study and effects in New Jersey

Google Images


Leafy Spurge (Euphorbia esula)

Look for this in sandy open uplands and dunes.

Important Links

YouTube identification video

USDA Species profile

Global Invasive Species Database profile

Google Images


Caper Spurge (Euphorbia lathyris)

Look for this wildflower in disturbed open uplands.

Important Links

NYS Ranking Form

Wikipedia entry

Dave's Garden gardener's experiences

German video showing exploding fruits

Google Images


Japanese Walnut (Juglans ailantifolia)


Photos from Wikipedia Commons

Japanese Walnut was found naturalizing in Orient, Suffolk County in 2010 by Daniel Atha. The trees were in a residential area and the edge of a woodland. This species has not been known to naturalize in North America until this find even though it has been in cultivation since 1860. It is not susceptible to walnut canker like our native walnuts.  More information can be found at the Wikipedia Commons site. It is unknown if this new population will persist but more surveys will be done in 2012 to understand its distribution in this area.

To identify the species you can use this key:

1. Terminal leaflet absent or reduced in size. Not sticky to the touch. Husk globoid, 3,5-8 cm wide (the largest resembling a tennis ball), 1-2 (-3-5)/short raceme. Nut globoid, 3-4 cm, with numerous warty ridges. .................................................................................................................................................... Juglans nigra

1. Terminal leaflet always present and well developed. Very sticky to the touch in all parts due to glandular hairs (in particular in spring, fading in autumn). Husk ovoid, 3-20/long raceme. Nut +/- ovoid, 3-6 cm long, smooth or with up to 8 +/- sharp longitudinal ridges.

            2. Bud +/- pyramidal, beige to pale brown (leaf scar upper margin emarginated). Husks 5-20/raceme. Nut smooth or ridged.            Juglans ailantifolia

            2. Bud +/- cylindrical, white to greyish (leaf scar upper margin flat!). Husks 3-5/raceme. Nut ridges razor-sharp (at least initially).       Juglans cinerea

Source: Jan De Langhe. The Juglandaceae Vegetative key to the species in Western European cultivation.  Ghent University Botanical Garden (24 September 2006, 3 November 2011)

Or this key:

1. Leaf scar with persistent fringe of hairs on upper edge

            2. Upper edge of these scar not notched, fringe of hairs conspicuous         Juglans cinerea

            2. Upper edge of leaf scar notched                                                                        Juglans ailantifolia

1. Leaf scar without persistent fringe of hairs on upper edge                                         Juglans nigra

Source: Notes on the temperate species of Juglans by John M. Grimshaw

Google Images


Giant Hogweed (Heracleum mantegazzanium)

Look for this very large wildflower in abandoned fields and on roadsides.


Important Links

DEC Giant Hogweed page

Massachusetts information page

News Alert 2011

Look-alike plants comparison table

Ontario giant hogweed identification and management

Google Images


Castor Aralia (Kalopanax septemloba)

Look for this tree and its seedlings in forest understory and forest edges and openings.

Important Links

Maryland Invader of the Month fact sheet

Wikipedia profile

Eastern Massachusetts photos

Dave's Garden gardener's experience

Google Images


Perennial Peppergrass (Lepidium latifolium)

Look for this wildflower in the upper margins of salt marshes between the salt grass and the shrubs.

Important Links

Plant Conservation Alliance profile

Perennial Pepperweed control handbook from Mass Audubon

University of Wisconsin Identification Video

Weed Society study on spread dynamics

California Invasive Plant Council profile

Google Images


Spotted Loosestrife (Lysimachia punctata)

Look for this wetland wildflower on the borders of lakes and ponds.

Important Links

Dave's Garden gardeners experiences

Great Lakes gardeners experiences

Missouri Botanical Garden information


Google Images


Himalayan Blackberry (Rubus bifrons)

Look for this shrub in disturbed forest edges, forests, meadows and fields.

Important Links

Identification information from Washington State

National Park Service Alert

Go Botany identification infomation

Tennessee control information

Google Images


Bog Bulrush (Schoenoplectiella mucronata)

Look for this sedge in disturbed, shallow, open, wet areas.

Important Links

National Park Service plant alert

Plant Invaders of Mid-Atlantic Natural Areas (page 24)

Dryades Project photos

Google Images


Water Chestnut (Trapa natans)

Look for this floating aquatic plant on the surface of lakes and ponds.

Important Links

New York Sea Grant fact sheet

Global Invasive Species Database profile

USDA profile

Chesapeake Bay Management Plan

Google Images


European High Bush Cranberry (Viburnum opulus var. opulus)

Look for this shrub on the borders of wetlands, streams, and in wet forests.

Important Links

Native Plants & Wildlife Gardens identification information

US Forest Service fact sheet

Chicago Region Virtual Herbarium fact sheet

Cornell Viburnum leaf beetle information

Google Images


Oriental False Hawksbeard (Youngia japonica)

Look for this wildflower in the understory of woodlands.

Important Links

Carolina Nature fact sheet

Description by Rufino Osorio photos

Habitat and spread in North Carolina

Google Images