This tiny little plant has often turned up in the wet tracks of logging roads and other constantly muddy areas. It has been theorized that these areas may be mimicking the trails of large extinct mammals like mastodons where this plant may have thrived in the past. The genus name means "beautiful hairs" and refers to the tiny threadlike stems.
There are 10 existing populations but all of them are small, only covering less than 30 square meters each. Since they occupy small disturbed areas they may not persist. There are only five historical records but with better knowledge of its habitat and a better search image this plant may be found more often.
Only one of the 10 existing populations has been surveyed more than once and that population remained the same over three years. More survey work is needed to determine short term trends.
There are a few historical records of this species in New York so it has never been common and there are now more existing populations than known historical populations. Therefore the long-term trend seems stable to slightly increasing.
Terrestrial starwort occurs in areas of human disturbance, especially in the open wet soil along old secondary roads, or in the case of one occurrence, at a horse stable. Plants may be threatened by the improper maintenance of these roads or by the upgrading of the roads and open soil areas to more stable surfaces. Conversely it may also be threatened by the abandonment of these habitats and succession by more aggressive herbaceous and woody species. A severe drought could also kill plants.
The open soil habitat of this species needs to be maintained through continued disturbance that does not also directly destroy the plants.
More research is needed into habitat preference because it seems to occur in habitats that are very common throughout New York. Why does it prefer only small portions of this common habitat?
Terrestrial starwort is apparently willing to occupy a broad range of habitats, provided that its microhabitat (bare, muddy ground) is available. Thus it has been discovered in New York at mud flats, pastures, pond shores, driveways, and both upland and wetland forests (New York Natural Heritage Program 2007). Damp, usually shaded soil (Gleason & Cronquist 1991). Damp earth, fallow fields, footpaths, etc. (Fernald 1970).
In New York most of our existing sites for Terrestrial starwort are in the Hudson Valley from Rockland County north to Columbia County, with one extant site known on Long Island. There are scattered historical records from Staten Island, the Adirondacks, and Oneida County.
Terrestrial starwort is found in most of the states in the eastern half of the U.S., as well as in New Brunswick.
Terrestrial starwort is a tiny, annual herb. Its stems are 2-5 cm long, creeping, and have entire, opposite leaves only 2-5 mm long. The flowers are borne singly in the leaf axils, and are either male or female, lacking petals or sepals and consisting of only either a single stamen or a single pistil. The female flowers produce fruit .5-.7mm long and up to 1mm wide, with persistent styles.
Flowering or fruiting specimens may be necessary for identification.
This is the only terrestrial Callitriche in New York. When in a vegetative state, it is more likely to be confused with some common liverworts. It may sometimes be found along the edge of a tidal or mudflat area, but most likely not in an area where it may be submerged. In this environment, fruiting specimens are needed to distinguish it from the other tiny mudflat plants.
Callitriche terrestris flowers from mid April through July, and the fruits persist from July through September.
The time of year you would expect to find Terrestrial Water Starwort fruiting in New York.
Terrestrial Water Starwort
Callitriche terrestris Raf.
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.
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. 2021. 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.
Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.
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
Weldy, Troy W. and David Werier. 2005. New York Flora Atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research. University of South Florida]. New York Flora Association, Albany, NY. Available on the web at (http://newyork.plantatlas.usf.edu/).
Information for this guide was last updated on: January 18, 2008
Please cite this page as:
New York Natural Heritage Program. 2021. Online Conservation Guide for Callitriche terrestris. Available from: https://guides.nynhp.org/terrestrial-starwort/. Accessed January 22, 2021.