Terrestrial Water Starwort

Callitriche terrestris Raf.

Callitriche terrestris
Troy Weldy

Dicotyledoneae (Dicots)
Plantaginaceae (Plantain Family)
State Protection
Listed as Threatened by New York State: likely to become Endangered in the foreseeable future. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
Imperiled or Vulnerable in New York - Very vulnerable, or vulnerable, to disappearing from New York, due to rarity or other factors; typically 6 to 80 populations or locations in New York, few individuals, restricted range, few remaining acres (or miles of stream), and/or recent and widespread declines. More information is needed to assign either S2 or S3.
Global Conservation Status Rank
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).


Did you know?

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.

State Ranking Justification

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.

Short-term Trends

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.

Long-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.

Conservation and Management


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.

Conservation Strategies and Management Practices

The open soil habitat of this species needs to be maintained through continued disturbance that does not also directly destroy the plants.

Research Needs

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).

Associated Ecological Communities

  • Brackish tidal marsh* (guide)
    A marsh community that occurs where water salinity ranges from 0.5 to 18.0 ppt, and water is less than 2 m (6 ft) deep at high tide. The vegetation in a brackish tidal marsh is dense and dominated by tall grass-like plants.
  • Chestnut oak forest (guide)
    A hardwood forest that occurs on well-drained sites in glaciated portions of the Appalachians, and on the coastal plain. This forest is similar to the Allegheny oak forest; it is distinguished by fewer canopy dominants and a less diverse shrublayer and groundlayer flora. Dominant trees are typically chestnut oak and red oak.
  • Freshwater intertidal mudflats (guide)
    A sparsely vegetated community characterized by low rosette-leaved aquatics. This community occurs on exposed intertidal mudflats where the water is fresh (salinity less than 0.5 ppt). This community is best developed where mudflats are nearly level so that broad expanses are exposed at low tide. The plants are completely submerged in 0.9 to 1.2 m (3 to 4 ft) of water at high tide and they are usually coated with mud.
  • Hemlock-northern hardwood forest (guide)
    A mixed forest that typically occurs on middle to lower slopes of ravines, on cool, mid-elevation slopes, and on moist, well-drained sites at the margins of swamps. Eastern hemlock is present and is often the most abundant tree in the forest.
  • Oak-tulip tree forest* (guide)
    A hardwood forest that occurs on moist, well-drained sites in southeastern New York. The dominant trees include a mixture of five or more of the following: red oak, tulip tree, American beech, black birch, red maple, scarlet oak, black oak, and white oak.
  • Pastureland
    Agricultural land permanently maintained (or recently abandoned) as a pasture area for livestock.
  • Red maple-hardwood swamp (guide)
    A hardwood swamp that occurs in poorly drained depressions, usually on inorganic soils. Red maple is usually the most abundant canopy tree, but it can also be codominant with white, green, or black ash; white or slippery elm; yellow birch; and swamp white oak.

* probable association but not confirmed.

Associated Species

  • Juncus tenuis (path rush)
  • Oxalis stricta (common yellow wood sorrel)
  • Plagiomnium cuspidatum
  • Plantago major (common plantain)
  • Polytrichum
  • Sagina japonica (Japanese pearlwort)
  • Symphyotrichum dumosum (bushy-aster)
  • Taraxacum officinale (common dandelion)
  • Trifolium repens (white clover)


New York State Distribution

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.

Global Distribution

Terrestrial starwort is found in most of the states in the eastern half of the U.S., as well as in New Brunswick.

Identification Comments

General Description

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.

Best Life Stage for Proper Identification

Flowering or fruiting specimens may be necessary for identification.

Similar Species

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.

Best Time to See

Callitriche terrestris flowers from mid April through July, and the fruits persist from July through September.

  • Fruiting

The time of year you would expect to find Terrestrial Water Starwort fruiting in New York.

Terrestrial Water Starwort Images


Terrestrial Water Starwort
Callitriche terrestris Raf.

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Plantaginales
          • Family Plantaginaceae (Plantain Family)

Additional Common Names

  • Starwort
  • Terrestrial Starwort


  • Callitriche austinii Engelm
  • Callitriche deflexa var. austinii (Engelm.) Hegelm.
  • Callitriche deflexa var. deflexa

Additional Resources

Best Identification Reference

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.

Other References

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. 2024. 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/).


About This Guide

Information for this guide was last updated on: January 18, 2008

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Callitriche terrestris. Available from: https://guides.nynhp.org/terrestrial-starwort/. Accessed April 17, 2024.