There is one verified occurrence; about 20 historical occurrences.
The short-term threats are unknown.
This species has been reduced in number of occurrences from its historical range.
Lake shoreline development is a threat to this species.
Management needs are unknown.
Habitat preferences should be studied.
The only known, extant site for Common Mare's-tail in New York is a shallow bay with a peaty bottom, where the plants grow along a shoreline of a flooded former bog. Little information is available from the historical sites, which include major rivers, shallow pools, and swamps (New York Natural Heritage Program 2011). Damp shores and shallow water of ponds, lakes, streams, and ditches (Crow and Hellquist 2000). In shallow, quiet water, or seldom on mud (Gleason and Cronquist 1991).
* probable association but not confirmed.
Hippuris vulgaris is currently extant in Franklin, Essex, Lewis, and St. Lawrence County and historically known from Seneca and Washington County
Mare's tail is found throughout the western US and along the northern tier of states in the central US. It extends east from Michigan where it becomes rare from New York through Vermont and New Hampshire to Maine. North of the US it is circumpolar in Canada, Europe and Asia.
Mare's tail has a soft but stiffly erect stem that is unbranched and about 2-6 decimeters tall. The whorls of leaves that are out of the water are numerous and crowded, with widely spreading linear leaves that are thick and firm and 1-3 cm long by 1-3 mm wide. The flowers and fruits are sessile just above the each leaf. The submersed stems have longer internodes and lax leaves.
Mare's tail has a soft but stiffly erect stem that is unbranched and about 2-6 decimeters tall. The whorls of leaves that are out of the water are numerous and crowded, with widely spreading linear leaves that are thick and firm and 1-3 cm long by 1-3 mm wide. The flowers and fruits are sessile just above the each leaf. The submersed stems have longer internodes and lax leaves.
Mare's tail can be identified in the vegetative stage with or without flowers and fruits.
Young stands of horsetail may be mistaken for mare's tail but no other emergent plant looks like it.
Common Mare's-tail has inconspicuous flowers, so it can be detected equally well whenever its leaves are emergent, from July until first frost.
The time of year you would expect to find Mare's Tail vegetative, flowering, and fruiting in New York.
Mare's Tail
Hippuris vulgaris L.
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. 2023. New York Natural Heritage Program Databases. Albany, NY.
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: February 1, 2023
Please cite this page as:
New York Natural Heritage Program. 2023.
Online Conservation Guide for
Hippuris vulgaris.
Available from: https://guides.nynhp.org/mares-tail/.
Accessed September 24, 2023.