The species name is Latin for comb-like and refers to the appearance of the dissected leaves (Fernald 1950).
There are six existing populations and three of them consist of multiple ponds that are hydrologically connected. Most of the populations are on protected parkland, but they may still be subject to some disturbance. There are two historical populations from the 1920s that have not been resurveyed.
Most of the populations have been surveyed at least twice and their short-term trend seems to be stable. However, fluctuating water levels make understanding the exact trend difficult.
The long-term trend appears stable as there are as many or even more populations now than were known in the past. This is a result of more detailed surveys in the 1980s and the protection of many of the coastal plain ponds.
Some ponds have seen too much development along the shoreline which threaten populations with direct disturbance by trampling and ATV use. The invasion of Phragmites is also a threat to a few populations.
The pondshores need to be protected from direct disturbance by ATVs and excessive trampling. Exotic invasive species must be prevented from colonizing the shores and present populations must be eliminated. A natural buffer of at least 200 feet should be established around the ponds to prevent excessive runoff and pollution events.
In New York this plant occurs almost exclusively on coastal plain pondshores. One occurrence occurs in a sedge meadow surrounded by wetland shrubs and another occurs in an artificial pond with a Sphagnum substrate surrounded by a maple swamp (New York Natural Heritage Program 2012). Sandy bogs of the coastal plain (Gleason and Cronquist 1991). Peaty or muddy quagmires, savannas and shallow water (Fernald 1950).
Long island and lower Hudson Valley.
It is most common along the Atlantic and Gulf Coastal Plains from southern New Jersey south to northern Florida and west to eastern Texas. Farther north it is rare and scattered from Long Island to southern Maine except for Massachusetts where it is more common. It extends inland in the Southeast to central Tennessee.
Comb-leaved mermaid-weed is a short aquatic plant with horizontal stems that root at the base and produce erect branches with leaves that stick out of the water. All of the leaves are deeply lobed into 6-12 narrow segment pairs that give the leaf a comb-like appearance (pinnatisect). The tiny single flowers (sometimes in twos or threes) arise in the axils of the upper leaves and have 3 green triangular sepals that enclose 3 stamens and 3 pinkish, frilly styles. There are no petals. The fruit is bony and ridged, sharply 3-angled with nearly flat sides. It has 3 seeds (Gleason and Cronquist 1991).
The comb-like leaves are the key character for identification, so this plant may be identified whenever it can be found.
The more widespread Proserpinaca palustris, common mermaid-weed, has emersed leaves that are oblong and merely toothed instead of pinnatisect. The submerged leaves are pinnatisect (Gleason and Cronquist 1991).
Comb-leaved Mermaid-weed emerges in late June and may persist into October.
The time of year you would expect to find Comb-leaved Mermaid Weed vegetative in New York.
Comb-leaved Mermaid Weed
Proserpinaca pectinata Lam.
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. Corrected printing (1970). D. Van Nostrand Company, 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. 2019. New York Natural Heritage Program Databases. Albany, NY.
Penskar, M.R. 2009. Special plant abstract for Proserpinaca pectinata (Comb-leaved Mermaid-weed). Michigan Natural Features Inventory, Lansing, MI. 3 pp.
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
This guide was authored by: Stephen M. Young
Information for this guide was last updated on: September 6, 2012
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Proserpinaca pectinata. Available from: https://guides.nynhp.org/comb-leaved-mermaid-weed/. Accessed March 20, 2019.