Sagina decumbens in flower Stephen M. Young

Sagina decumbens in flower
Stephen M. Young

Class
Dicotyledoneae (Dicots)
Family
Caryophyllaceae (Pink Family)
State Protection
Endangered
Listed as Endangered by New York State: in imminent danger of extirpation in New York. 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
S1
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
G5T5
Secure globally - Both the species as a whole and the subspecies/variety are common in the world; widespread and abundant (but may be rare in some parts of its range).

Summary

Did you know?

The species name that means lying down or almost prostrate. If you want to see this tiny plant you may have to lie down too!

State Ranking Justification

There is one existing population of about 200 plants. It occurs in an unprotected area that is not actively managed. There are six historical populations from the late 1800s to the mid-1940s that need to be resurveyed.

Short-term Trends

The existing population has been resurveyed once and its short-term trend appears stable.

Long-term Trends

The number of populations seems to have declined over the last century but more survey work is needed to confirm this. This plant is difficult to survey for because of its small size and resemblance to other more common plants.

Conservation and Management

Threats

Direct trampling by humans is the biggest threat although its habitat needs to be maintained by disturbance.

Conservation Strategies and Management Practices

Maintain a disturbance regime that perpetuates suitable habitat. This plant needs some disturbance to prevent succession of larger grasses or other woody species.

Research Needs

Research is needed to better understand the specific habitat conditions preferred by this species. It occurs in a seemingly common habitat which makes it difficult to survey.

Habitat

Habitat

In New York, the plants occur on a dredge spoil shore of an ocean bay. They are on a strip of dry, but over washed and occasionally bare land beside a boat basin-breakwater. They are also along a grassy trail in a more sandy area between stands of Phragmites. A historical record is from a shady grassy roadside (New York Natural Heritage Program 2012). Wet places were dry, sandy soil (Gleason and Cronquist 1991). Moist or dryish sandy fields, paths and open spots in woods (Fernald 1950).

Associated Ecological Communities

  • Dredge spoils
    An upland site where dredge spoils have been recently deposited. On sandy dredge spoils along the Hudson River, characteristic species of early successional deposits include winged pigweed, lovegrass, purple sandgrass, tall crabgrass, and field sandbur; cottonwood is common on late successional deposits. Maritime dredge spoil islands along the seacoast of Long Island provide nesting habitat for herring gull, least tern, and piping plover.
  • Dredge spoil wetland
    A wetland in which the substrate consists of dredge spoils; reedgrass is a characteristic species.

Associated Species

  • Digitaria
  • Rumex
  • Solidago sempervirens (northern seaside goldenrod)
  • Spergularia

Range

New York State Distribution

This small wildflower is currently known from Suffolk County on Long Island. There are old unconfirmed reports from Nassau County, Staten Island, and Manhattan.

Global Distribution

This is a wildflower of the South-Central and Eastern United States extending north to southern Illinois, and east to eastern Pennsylvania, New Jersey, Long Island and southern New England. It extends south through northern Florida.

Best Places to See

  • No populations are known from locations accessible to the public.

Identification Comments

General Description

Small-flowered pearlwort is a tiny annual plant with many slender branches that grow in all directions to form small mats from 3-10 cm tall. The leaves are opposite and linear and without stipules. The flowers are along and at the tops of the branches on hairless pedicels about 10-15 mm long. There are five sepals alternating with five white petals and there are of about the same length. There are five or ten stamens and five separate styles. The capsule is 2-3 mm long and ellipsoid and longer than the sepals that become erect and appressed to it. The tiny seeds are flattened, essentially smooth, and with a groove between the two upper angles (Gleason and Cronquist 1991).

Identifying Characteristics

Distinguishing characteristics: annual; stem erect, ascending or rarely decumbent; pedicels straight, not hooked after anthesis; sepals 5 (rarely 4), closely appressed-ascending; capsule 1-2 mm thick, its 5 (rarely 4) valves nearly erect after dehiscence; seeds reddish-brown, delicately marked with slender ridges. Best life stage for ID: in fruit. Characteristics needed to ID: plant with roots and leaves, preferably with fruits.

Best Life Stage for Proper Identification

The best time to identify the species is when it is in flower or fruit.

Similar Species

There are two similar species in the genus Sagina. Sagina procumbens is widespread in the state but is a perennial and usually has basal rosettes or sterile shoots. It has four sepals (rarely five) which remain spreading in fruit. Sagina japonica is an uncommon weedy species from Japan and China that has slightly succulent leaves and flower pedicels that are glandular-hairy at least in the upper half. The fruit is shorter and more rounded and the seeds are plump, dark brown, beset with little projections, and without a dorsal groove. Minuartia caroliniana also looks similar but it occurs on sand dunes and has three styles, not five, and its leaves are bunched together at the bottom (Gleason and Cronquist 1991).

Best Time to See

Flowers mid-May to late July.

  • Flowering

The time of year you would expect to find Trailing Pearlwort flowering in New York.

Trailing Pearlwort Images

Taxonomy

Trailing Pearlwort
Sagina decumbens ssp. decumbens None

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Caryophyllales
          • Family Caryophyllaceae (Pink Family)

Additional Common Names

  • Pearlwort

Synonyms

  • Sagina apetala Ard. [Misapplied to some New York specimens.]
  • Sagina subulata var. smithii A. Gray
  • Sagina decumbens var. smithii (A. Gray) Watson
  • Spergula decumbens Ell.

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2005. Flora of North America North of Mexico, Volume 5, Magnoliophyta: Caryophyllidae, Part 2. Oxford University Press, New York.

Other References

Clemants, Steven and Carol Gracie. 2006. Wildflowers in the Field and Forest. A Field Guide to the Northeastern United States. Oxford University Press, New York, NY. 445 pp.

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.

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. 2019. 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

Links

About This Guide

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 Sagina decumbens ssp. decumbens. Available from: https://guides.nynhp.org/trailing-pearlwort/. Accessed May 26, 2019.

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