Illustration of Omalotheca sylvatica USDA Plants Database

Illustration of Omalotheca sylvatica
USDA Plants Database

Class
Dicotyledoneae (Dicots)
Family
Asteraceae (Aster 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
G4
Apparently Secure globally - Uncommon in the world but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors.

Summary

Did you know?

This species has been found only once in New York but more occurrences could probably be found in the Adirondacks if more searches are done.

State Ranking Justification

There are two existing populations with hundreds of plants each and no other historical populations.

Short-term Trends

In the United Kingdom, where approximately one-quarter of the world's population of this plant are reported, researchers estimate this plant has declined by about 50% in the last 25 years (Edinburgh Biodiversity Partnership). With only a few known and historical New York populations, assessing the trend here is very difficult. More information on historical distribution and current known populations are needed before a trends assessment can be evaluated.

Long-term Trends

We have no historical records of this plant. The first specimen from New York was collected in 1989. A second population was discovered in 2003, although this second population may be considered adventive. More information is needed on possible older records in New York before the long-term trends can be assessed. We speculate that this plant was always rare in New York.

Conservation and Management

Threats

This plant may be threatened by liming of soils, changes to land management, and succession. This is a disturbance-dependent species with one population growing in an area that receives periodic mowing and changes to the current mowing pattern could reduce the population. More research is needed to fully assess the threats of this plant.

Conservation Strategies and Management Practices

As a plant of early successional sites and natural disturbances, natural openings or even soil scrapes may be necessary for the persistence of this plant. Retain the current mowing pattern and avoid the use of herbicides, pesticides, and/or fertilizer where the plants grow.

Habitat

Habitat

There are two populations known from New York -- one from a flat river terrace with shallow, sandy soils, and one from a dense patch of flattened oat-grass (Danthonia compressa) on an old logging road (New York Natural Heritage Program 2013). Open woods, boggy woods, rocky slopes, clearings, fields, borders of woods, roadsides, muddy banks, disturbed sites (FNA 2006a). Single collection from a dry wooded hillside (Rhoads and Block 2000). A single collection along old trails in hardwood forest (Voss 1996). Open woods and waste places (Gleason and Cronquist 1991). Clearings, rocky slopes, borders of woods, and fields (Fernald 1950).

Associated Ecological Communities

  • Boreal heath barrens* (guide)
    A dwarf shrubland or shrub-savanna dominated by heath or heath-like shrubs. Boreal heath barrens occur on nearly level outwash plains of the Adirondacks, in frost pockets lying in valleys. * probable association but not confirmed.
  • Mowed roadside/pathway
    A narrow strip of mowed vegetation along the side of a road, or a mowed pathway through taller vegetation (e.g., meadows, old fields, woodlands, forests), or along utility right-of-way corridors (e.g., power lines, telephone lines, gas pipelines). The vegetation in these mowed strips and paths may be dominated by grasses, sedges, and rushes; or it may be dominated by forbs, vines, and low shrubs that can tolerate infrequent mowing.
  • Open alpine community* (guide)
    An open community consisting of a mosaic of sedge/dwarf shrub meadows, dwarf heath shrublands, small boggy depressions, and exposed bedrock covered with lichens and mosses. The open alpine community occurs above timberline (about 4,900 ft or 1,620 m) on the higher mountain summits and exposed ledges of the Adirondacks. The flora includes arctic-alpine species that are restricted (in New York) to these areas, as well as boreal species that occur in forests and bogs at lower elevations. The soils are thin and organic, primarily composed of peat derived from peat mosses (Sphagnum spp.) or black muck. The soils are often saturated because they can be recharged by atmospheric moisture. * probable association but not confirmed.
  • Successional northern hardwoods*
    A hardwood or mixed forest that occurs on sites that have been cleared or otherwise disturbed. Canopy trees are usually relatively young in age (25-50 years old) and signs of earlier forest disturbance are often evident. Characteristic trees and shrubs include any of the following: quaking aspen, big-tooth aspen, balsam poplar, paper birch, gray birch, pin cherry, black cherry, red maple, and white pine. * probable association but not confirmed.
  • Unpaved road/path
    A sparsely vegetated road or pathway of gravel, bare soil, or bedrock outcrop. These roads or pathways are maintained by regular trampling or scraping of the land surface. The substrate consists of the soil or parent material at the site which may be modified by the addition of local organic material (woodchips, logs, etc.) or sand and gravel. Abandoned railroad beds where tracks have been removed are included here. One characteristic plant is path rush.

Associated Species

  • Antennaria neglecta (field pussy-toes)
  • Cerastium fontanum
  • Danthonia compressa (northern oat grass)
  • Danthonia spicata (poverty grass)
  • Juncus tenuis (path rush)
  • peltigera
  • Plantago major (common plantain)
  • Prunella vulgaris
  • Quercus alba (white oak)
  • Taraxacum officinale (common dandelion)
  • Trifolium repens (white clover)
  • Veronica filiformis (thread-stalked speedwell)
  • Veronica serpyllifolia

Range

New York State Distribution

There are currently only two populations. The first is located along a logging road in the Adirondacks (Herkimer County) and the second is located within Letchworth State Park in Wyoming County. There are no other known historical records.

Global Distribution

Wioodland Cudweed is a northern species found in the the northern tier of US states from Wisconsin east, south of Pennsylvanaia, and extending from Ontario to the Maritime Provinces in Canada. It may represent an introduced population of a closely related, circumboreal species of Omalotheca.

Identification Comments

General Description

Omalotheca sylvatica is a native perennial herb of the aster family, growing to 10-70 cm in height with a silvery-silky hairy covering much of its leaves. The late-appearing basal leaves are 2-10 mm wide with a single mid-rib. As with all asters, the infloresences are arranged radially into "heads" of many separate ray and disc flowers, superficially resembling a single flower. The flowering stems are stiffly erect with numerous linear, ascending leaves. The inflorescence is an elongated leafy stem with 10 to many flowering heads in an interrupted, loose spike from 4 to 35 cm tall. The whorls of bracts (involucres) subtending the flowering heads are 5 to 6.5 mm long. The individual bracts (phyllaries) are light straw-colored or greenish at the base with a conspicuous V-shaped dark brown spot located just below the thin, membranous, translucent (hyaline) tips. The fruits are covered with appressed bristle-like hairs. The tuft of bristly hairs (pappus) present on the fruit are fused together at their base (connate), and fall off as a unit.

Identifying Characteristics

Omalotheca sylvatica is a native perennial herb growing to 10-70 cm in height with silvery-silky hairs covering the lower (abaxial) surfaces of its leaves. The late-appearing basal leaves are 2-10 mm wide with a single mid-rib. The flowering stems are stiffly erect with numerous linear, ascending leaves. The inflorescence is an elongated leafy stem with 10 to many flowering heads in an interrupted, loose spike configuration 4 to 35 cm high and occupying 1/3 to 5/6 of the entire height of the plant. The whorl of bracts subtending the flowering heads (involucres) is 5 to 6.5 mm long, rounded to obtuse, the individual bracts (phyllaries) are light straw-colored or greenish at the base with a conspicuous V-shaped dark brown spot located just below the thin, membranous, translucent (hyaline) tip. The fruits (cypselae) are cylindric to spindle-shaped and covered with minute appressed, rigid, bristle-like, straight hairs. The tuft of bristly hairs (pappus) present on the fruit are fused together at their base (connate), and fall off as a unit.

Best Life Stage for Proper Identification

For positive idenitification the entire plant with leaves and intact flowers or fruits is needed.

Similar Species

Omalotheca sylvatica is the only Omalotheca found in New York. The closely-related genera Gnaphalium and Pseudognaphalium have only annual or biennial species in New York and can be distinguished by their lack of a persisent, horizontally growing underground stem (rhizome). O. supina, an alpine species known from high elevations in northern New England, is typically a smaller plant overall, and its pappus bristles are not connate.

Best Time to See

This plant typically flowers from July to September. Fruiting typically begins in late August with both the plants and fruits persisting through the early frost.

  • Vegetative
  • Flowering
  • Fruiting

The time of year you would expect to find Woodland Cudweed vegetative, flowering, and fruiting in New York.

Woodland Cudweed Images

Taxonomy

Woodland Cudweed
Omalotheca sylvatica (L.) Schultz-Bip. & F.W. Schultz

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Asterales
          • Family Asteraceae (Aster Family)

Additional Common Names

  • Wood Cudweed
  • Chaffweed
  • Owl's-crown
  • Heath Cudweed
  • Woodland Arctic Cudweed

Synonyms

  • Gnaphalium sylvaticum

Additional Resources

Best Identification Reference

Flora of North America Editorial Committee. 2006a. Flora of North America North of Mexico. Vol. 19. Magnoliophyta: Asteridae, part 6: Asteraceae, part 1. Oxford University Press, New York. xxiv + 579 pp.

Other References

Edinburgh Biodiversity Partnership. No date. Heath Cudweed (Gnaphalium sylvaticum). Pdf downloaded from http://download.edinburgh.gov.uk/biodiversity/095%20Heath%20Cudweed.pdf. 2 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.

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.

Voss, Edward G. 1996. Michigan Flora Part III. Dicots Concluded (Pyrolaceae - Compositae). Cranbrook Institute of Science Bulletin 61 and University of Michigan Herbarium. 622 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

Zika, Peter F. 1990. The first records of Gnaphalium sylvaticum (Asteraceae) and Empetrum eamesii ssp. atroputpureum in New York State. Rhodora 92 (871): 120-125.

Links

About This Guide

This guide was authored by: Stephen M. Young, Elizabeth Spencer, Richard M. Ring.

Information for this guide was last updated on: April 2, 2013

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Omalotheca sylvatica. Available from: https://guides.nynhp.org/woodland-cudweed/. Accessed September 24, 2019.

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