Ranunculus micranthus plant Troy Weldy

Ranunculus micranthus plant
Troy Weldy

Class
Dicotyledoneae (Dicots)
Family
Ranunculaceae (Buttercup Family)
State Protection
Rare
A plant listed as Rare by New York State. Removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
S3
Vulnerable in New York - Vulnerable to disappearing from New York due to rarity or other factors (but not currently imperiled); typically 21 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.
Global Conservation Status Rank
G5
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).

Summary

Did you know?

The species name means tiny-flowered. You have to look hard for these flowers as they are so small and they are visible only during early spring. Fortunately flowers are not the only character that is needed for identification.

State Ranking Justification

There are 22 existing records and 10 of those are ranked good to excellent. More populations will probably be found with more exploration of the dry forests of the Lower Hudson region. There are about 5-10 historical records that could use more survey work.

Short-term Trends

Short-term trends seem stable although more survey work would result in a better understanding of how populations fluctuate with disturbance over time.

Long-term Trends

This has always been an uncommon plant in New York but the number of known populations has remained about the same during the last 100 years.

Conservation and Management

Threats

Some populations are threatened by invasive exotic plants, especially garlic mustard and Japanese silver grass. Some plants are close to human activity and may be trampled while woodland populations are subject to damage from logging.

Conservation Strategies and Management Practices

Maintain an open natural understory and prevent succession by invasive species.

Research Needs

Research is needed to determine how this species reacts to fire management and its ability to seed bank.

Habitat

Habitat

In New York, Ranunculus micranthus has been found most often on south and southeast-facing slopes of ridges and summits. It seems to prefer neither open grasslands or shrublands, nor closed forest, but partial shade and small openings. Many, though not all, of these sites have rich soils and high plant diversity, although it has also been collected from apparently acidic, sandstone-derived soils as well. This species has been found in a wide variety of forest types, from beech-sugar maple, to oak-hickory, to red cedar summits (New York Natural Heritage Program 2007). Rich woods and calcareous banks (Fernald 1970). Dry or moist woods (Gleason and Cronquist 1991).

Associated Ecological Communities

  • Acidic talus slope woodland (guide)
    An open to closed canopy woodland that occurs on talus slopes (slopes of boulders and rocks, often at the base of cliffs) composed of non-calcareous rocks such as granite, quartzite, or schist.
  • Appalachian oak-hickory forest (guide)
    A hardwood forest that occurs on well-drained sites, usually on ridgetops, upper slopes, or south- and west-facing slopes. The soils are usually loams or sandy loams. This is a broadly defined forest community with several regional and edaphic variants. The dominant trees include red oak, white oak, and/or black oak. Mixed with the oaks, usually at lower densities, are pignut, shagbark, and/or sweet pignut hickory.
  • Pitch pine-oak-heath rocky summit (guide)
    A community that occurs on warm, dry, rocky ridgetops and summits where the bedrock is non-calcareous (such as quartzite, sandstone, or schist), and the soils are more or less acidic. This community is broadly defined and includes examples that may lack pines and are dominated by scrub oak and/or heath shrubs apparently related to fire regime.
  • Pitch pine-oak-heath woodland (guide)
    A pine barrens community that occurs on well-drained, infertile, sandy soils. The structure of this community is intermediate between a shrub-savanna and a woodland. Pitch pine and white oak are the most abundant trees.
  • Pitch pine-scrub oak barrens (guide)
    A shrub-savanna community that occurs on well-drained, sandy soils that have developed on sand dunes, glacial till, and outwash plains.
  • Rocky summit grassland (guide)
    A grassland community that occurs on rocky summits and exposed rocky slopes of hills. Woody plants are sparse and may be scattered near the margin of the community. Small trees and shrubs may be present at low percent cover.

Associated Species

  • Acer saccharum (sugar maple)
  • Ailanthus altissima (tree-of-heaven)
  • Alliaria petiolata (garlic mustard)
  • Amelanchier arborea (downy shadbush)
  • Antennaria plantaginifolia (plantain-leaved pussy-toes)
  • Aquilegia canadensis (wild columbine, red columbine)
  • Arabidopsis lyrata
  • Aristolochia serpentaria
  • Asclepias quadrifolia (four-leaved milkweed)
  • Asplenium platyneuron (ebony spleenwort)
  • Asplenium trichomanes
  • Berberis thunbergii (Japanese barberry)
  • Boechera canadensis
  • Campanula rotundifolia (hare-bell)
  • Cardamine parviflora (small-flowered bitter cress)
  • Carex albicans (white-tinged sedge)
  • Carex appalachica (Appalachian sedge)
  • Carex blanda (eastern woodland sedge)
  • Carex cephalophora (oval-headed sedge)
  • Carex communis
  • Carex eburnea (bristle-leaved sedge)
  • Carex muehlenbergii
  • Carex pensylvanica (Pennsylvania sedge)
  • Carex platyphylla (broad-leaved sedge)
  • Carex retroflexa (reflexed sedge)
  • Carex willdenowii (Willdenow's sedge)
  • Carya glabra (pignut hickory)
  • Carya ovata
  • Comandra umbellata
  • Corydalis flavula (yellow corydalis)
  • Corydalis sempervirens
  • Danthonia compressa (northern oat grass)
  • Danthonia spicata (poverty grass)
  • Deschampsia flexuosa
  • Desmodium nudiflorum
  • dichanthelium clandestinum
  • Dichanthelium boscii (Bosc's rosette grass)
  • Dryopteris marginalis (marginal wood fern)
  • Elymus hystrix
  • Eurybia lin
  • Fallopia cilinodis (fringed bindweed)
  • Fallopia scandens (climbing false buckwheat)
  • Fraxinus americana (white ash)
  • Galium aparine (cleavers)
  • Galium circaezans (forest wild-licorice)
  • Helianthemum canadense
  • Heuchera americana
  • Hieracium paniculatum (panicled hawkweed)
  • Juniperus virginiana
  • Linaria vulgaris (butter-and-eggs)
  • Lonicera morrowii (Morrow's honeysuckle)
  • Microstegium vimineum (Japanese stilt grass)
  • Orobanche uniflora (one-flowered broom-rape)
  • Oryzopsis asperifolia (spreading white grass)
  • Ostrya virginiana (hop hornbeam, ironwood)
  • Oxalis stricta (common yellow wood sorrel)
  • Oxalis violacea (violet wood sorrel)
  • Paronychia canadensis (smooth forked-chickweed)
  • Prunus serotina
  • Pycnanthemum incanum
  • Quercus alba (white oak)
  • Quercus montana (chestnut oak)
  • Quercus rubra (northern red oak)
  • Rosa carolina
  • Rosa multiflora (multiflora rose)
  • Rumex acetosella
  • Saxifraga virginiensis
  • Schizachyrium scoparium
  • Silene caroliniana
  • Solidago bicolor (silver-rod)
  • Solidago caesia
  • Solidago puberula (downy goldenrod)
  • Staphylea trifolia (bladdernut)
  • Symphyotrichum undulatum (wavy-leaved-aster)
  • Tephrosia virginiana (goat's-rue)
  • Tilia americana
  • Triodanis perfoliata (common Venus's looking-glass)
  • Uvularia sessilifolia (wild-oats, sessile-leaved bellwort)
  • Vaccinium pallidum (hillside blueberry)
  • Viburnum acerifolium (maple-leaved viburnum)
  • Viburnum rafinesquianum
  • Viola palmata (three-lobed violet)

Range

New York State Distribution

Small-flowered Crowfoot is found from Columbia County in the Lower Hudson Valley south to New York City and east to Suffolk County on Long Island.

Global Distribution

Small-flowered Crowfoot is found from southern New England and the extreme southern New York south and west, roughly through the Mid-Atlantic states and Ohio River Valley, reaching its southwestern limits in Missippi, Arkansas, and Oklahoma. It is also disjunct to South Dakota.

Identification Comments

General Description

Small-flowered Crowfoot is an herbaceous perennial wildflower. It grows 11-40 cm tall. The stems and petioles are sparsely hairy. It has two distinctly different types of roots -- some hairlike (0.2-0.6 mm thick) and some with tuberous bases 1-2 mm thick. The basal leaves are persistent, the outer ones undivided and the inner ones 3-parted or divided into 3 leaflets. The stem leaves are usually deeply divided into 3-5 segments (some in turn deeply incised, shaped roughly like the footprint of a crow). The flowers have 5 pale yellow (sometimes white) petals 1.5 to 3.5 mm long. The fruit are beaked achenes, arranged on a glabrous, egg-shaped receptacle.

Best Life Stage for Proper Identification

Specimens with flowers or mature fruit, as well as the roots, stems, and leaves, are needed to positively identify this species.

Similar Species

Ranunculus abortivus may resemble Ranunculus micranthus, but differs by having glabrous or nearly glabrous stem and leaves, and the basal leaves of R. abortivus are very often cordate, while those of Ranunculus micranthus usually are not. R. abortivus has pubescent receptacles while those of R. micranthus are glabrous. Ranunculus abortivus is also usually found in moist to wet habitats, though it can occasionally be in dry settings.
Ranunculus allegheniensis may also resemble Ranunculus micranthus, but has glabrous stems and petioles and achenes with beaks 0.7-1.0 mm long, while those of R. micranthus are much shorter (.2 mm).

Best Time to See

Ranunculus micranthus flowers from May to early June, and the fruits persist through June or rarely into July.

  • Flowering
  • Fruiting

The time of year you would expect to find Small-flowered Crowfoot flowering and fruiting in New York.

Small-flowered Crowfoot Images

Taxonomy

Small-flowered Crowfoot
Ranunculus micranthus Nutt.

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Ranunculales
          • Family Ranunculaceae (Buttercup Family)

Synonyms

  • Ranunculus micranthus var. dilitescens (Greene) Fern.

Additional Resources

Best Identification Reference

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.

Other References

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Flora of North America Editorial Committee. 1997. Flora of North America, North of Mexico. Volume 3. Magnoliophyta: Magnoliidae and Hamamelidae.

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, R. S., and K. J. Dean. 1982. Ranunculaceae (Crowfoot family) of New York State. The State Education Department, Albany, New York.

New York Natural Heritage Program. 2005. Biotics Database. Albany, NY.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.

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/).

Links

About This Guide

Information for this guide was last updated on: December 29, 2008

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Ranunculus micranthus. Available from: https://guides.nynhp.org/small-flowered-crowfoot/. Accessed October 16, 2019.

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