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.
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 seem stable although more survey work would result in a better understanding of how populations fluctuate with disturbance over time.
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.
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.
Maintain an open natural understory and prevent succession by invasive species.
Research is needed to determine how this species reacts to fire management and its ability to seed bank.
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).
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.
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.
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.
Specimens with flowers or mature fruit, as well as the roots, stems, and leaves, are needed to positively identify this 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).
Ranunculus micranthus flowers from May to early June, and the fruits persist through June or rarely into July.
The time of year you would expect to find Small-flowered Crowfoot flowering and fruiting in New York.
Ranunculus micranthus Nutt.
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.
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://atlas.nyflora.org/).
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 January 17, 2019.