There are seven historical records from Long Island for this pondweed but it has not been documented there since 1952 when it was collected at Riverhead. There are a number of known locations in the Hudson Highlands though. The specific name means handsome since it is more colorful than most pondweeds.
There are approximately ten known populations and nearly 25 historical locations for the aquatic plant. As an aquatic plant, it may be subject to changes in water chemistry, aquatic herbicides, intensive recreational boating, and invasive species. Long Island has experienced a substational decline of this plant. More populations might be found, but there also a few populations with low predicted viability.
Very few follow-up surveys have been done of these populations so short-term trends are unknown.
While new populations have been found in Hudson Highlands there has been a substantial decline on Long Island.
Most of the populations are buffered from development but there is a chance that aquatic invasive plants could threaten plant numbers.
Monitor the growth and control of aquatic invasive plants.
Research into the physical parameters of this plant's water bodies would help to locate more populations.
A aquatic plant in the still or slowly moving water (1-2+ meters deep) of deep emergent marshes, small streams, small lakes/ponds, and open pools (New York Natural Heritage Program 2004). Shallow water (Gleason & Cronquist 1991).
* probable association but not confirmed.
An aquatic plant from the Hudson Valley, Long Island, and Oswego County. Most known populations today are located within the Hudson Highlands. New York is near the northern edge of its range.
An aquatic plant found chiefly along the coastal plain from southern Maine to Florida and Alabama. It is also known inland around southern Indiana to Missouri and Arkansas.
This is an aquatic plant of acidic waters with oval to heart-shaped, long-stalked, floating leaves on stems that are dark-purple spotted. It also has submerged, lance-shaped leaves that have 19-35 veins and are translucent with crinkled edges.
An aquatic plant with stems and petioles that are usually dark spotted. The median and upper submersed leaves are translucent, lanceolate to lance-linear, and not arcuate or cordate, These leaves can taper to a short petiole or be nearly sessile. They are 0.8-1.8 dm long and 1-3.5 cm broad. The floating leaves are ovate to roundish and cordate or broadly rounded at base. These floating leaves have 19- 35 nerves that are essentially uniform. The fruits are rounded or lobed at base with the fruit body 3-4 mm long and 2.6-3.4 mm broad. This species is most easily distinguished by the broad submersed leaves, cordate floating leaves, and dark spotted stems.
Only vegetative plants with stems and leaves are necessary for proper identification.
Potamogeton amplifolius does not have a black spotted stem.
Vegetative plants emerge by mid-May and flowers have formed by mid-June. The plants can be found throughout the summer and into the early fall season. Since it can be identified vegetatively, surveys may be conducted anytime between mid-May and mid-October.
The time of year you would expect to find Spotted Pondweed vegetative and fruiting in New York.
Spotted Pondweed
Potamogeton pulcher Tuckerman
Crow, Garrett E. and C. Barre Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America: A revised and enlarged edition of Norman C. Fassett's a Manual of Aquatic Plants. Volume One: Pteridophytes, Gymnosperms, and Angiosperms: Dicotyledons. The University of Wisconsin Press. Madison, Wisconsin. 536 Pages.
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.
Hellquist, C.B. and G.E. Crow 1980. Aquatic Vascular Plants of New England: Part 1. Zosteraceae, Potamogetonaceae, Zannichelliaceae, Najadaceae. New Hampshire Agricultural Experiment Station University of New Hampshire. Station Bull. 515.
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.
Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.
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.
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.
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
Information for this guide was last updated on: June 22, 2005
Please cite this page as:
New York Natural Heritage Program. 2023.
Online Conservation Guide for
Potamogeton pulcher.
Available from: https://guides.nynhp.org/spotted-pondweed/.
Accessed December 5, 2023.