Dwarf White Birch. Summary. Protection Endangered in New York State, not listed federally.

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1 Dwarf White Birch Scientific Name Family Name Betula minor (Tuckerman) Fern. Betulaceae Birch Family Did you know? This species was orginally described as only a variety of the taller, more common paper birch, and the species name "minor", which means smaller, was probably chosen to reflect that this species resembles a smaller version of paper birch. Summary Protection Endangered in New York State, not listed federally. This level of state protection means: listed species are those with: 1) 5 or fewer extant sites, or 2) fewer than 1,000 individuals, or 3) restricted to fewer than 4 U.S.G.S. 7 ½ minute topographical maps, or 4) species listed as endangered by U.S. Department of Interior. Rarity G4G5Q, S1 A global rarity rank of G4G5Q means: Apparently or Demonstrably Secure globally - Uncommon to common 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. More information is needed to assign a single conservation status. The Q indicates this species status as a distinctive full species is uncertain. A state rarity rank of S1 means: This plant is endangered/critically imperiled in New York because of extreme rarity (typically 5 or fewer populations or very few remaining individuals) or is extremely vulnerable to extirpation from New York due to biological NYNHP Conservation Guide - Dwarf White Birch (Betula minor)

2 factors. Conservation Status in New York There are three known extant populations and a fourth population that needs to be verified. A fifth population has not been seen since 1958 but may still be extant. All of these populations are very small (under 50 individuals), are restricted to the alpine regions of the highest summits of the Adirondacks, and occur within about 5 air miles of each other. Short-term Trends There are no clear data indicating how the populations are doing in the short-term. Long-term Trends One population has not been seen since 1958 although it has been looked for. Therefore, further survey work is needed to determine if this population is still extant. The other three confirmed populations each have under 50 individuals. Overall, long-term trends are unclear but may indicate a decline. Conservation and Management Threats Trampling by hiker traffic is a potential threat at one and perhaps at more of the populations. Conservation Strategies and Management Practices The Summit Steward program which works to inform hikers of the fragile nature of alpine plants is a critical program which is helping to reduce trampling of alpine vegetation. This program and other efforts designed to reduce trampling of alpine meadows are needed. Research Needs Precise counts and locations of all individuals should be noted during inventory work so that population trends can be better assessed. One population that has not been seen since 1958 needs more survey work in order to determine whether it is still extant. Another probable population needs to have the identification of Betula minor confirmed. Habitat In New York, this species grows exclusively on or near the highest summits in the Adirondacks. It occurs in open alpine meadows and in sub-alpine krummholz often among rock outcrops (New York Natural Heritage Program 2007). Rocky slopes, barrens, and subalpine summits (Furlow 1997). In New York: found only on rocky alpine summits; elsewhere on rocky barrens and slopes (Furlow and Mitchell 1990). NYNHP Conservation Guide - Dwarf White Birch (Betula minor) 2

3 Associated Ecological Communities Alpine Krummholz A dwarf woodland dominated by balsam fir that occurs at or near the summits of the high peaks of the Adirondacks. Alpine Meadow A very low-growing community similar in many ways to arctic tundra. Alpine meadows occur above timberline on the higher mountain summits and exposed ridges of the Adirondacks. Dwarf shrublands, small grassy meadows, small boggy depressions, and exposed bedrock with lichens and mosses are all commonly found within this broadly classified community. Associated Species Bog Blueberry (Vaccinium uliginosum) Identification Comments In New York, Dwarf white birch is a depressed, small tree or shrub with 1 to several trunks that grows up to 6 or occasionally 10 feet. The twigs are often dotted with large resinous glands. The leaves are about.5 to 1.5 inches long and have coarse and irregular double teeth along the edges. They are yellowish on the undersides. The flowers are small and inconspicuous but grow in dense clusters known as catkins. Separate catkins are composed entirely of female or male flowers. Best Life Stage for Identifying This Species This species can be identified vegetatively but mature fruits are helpful and collections or photos should include these. The Best Time to See This species can be surveyed for once the leaves are mature in June, although since it is helpful to have fruits the best time to survey for this species is from August through September. Vegetative Flowering Fruiting Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec The time of year you would expect to find Dwarf White Birch in New York. NYNHP Conservation Guide - Dwarf White Birch (Betula minor) 3

4 Similar Species Betula glandulosa grows in the same alpine habitats as B. minor. It has doubly serrate leaves with mostly an acuminate to acute apex, while B. minor has singly toothed leaves with a rounded apex. Betula cordifolia, which also sometimes grows near B. minor, differs in being a tall tree up to 15(-25) meters tall (although in sub-alpine settings it is dwarfed and stunted) with relatively tight bark in mature individuals, has leaves (3-)6-10(-14) cm long with a usually cordate or truncate base and 9-12 pairs of lateral veins, fruiting female catkins cm long, and wings of the fruits mm broad, while B. minor is a shrub or small tree to 2(-3) meters tall with exfoliating bark in mature individuals, has leaves (1.5-) (-4.5) cm long with a rounded or cuneate base and 2-6 pairs of lateral veins, fruiting female catkins mm long, and wings of fruits mm wide. Its leaves are intermediate in size between B. cordifolia and B. glandulosa. Conservation Comments E. Lepage (1976 in Furlow 1997) interprets the type of B. minor to be a hybrid between B. papyrifera and the name he uses for the dwarf species, B. saxophila. Furlow (1997) sees the characters of the type of B. minor falling easily within the variation of B. saxophila and therefore retains the name B. minor for the dwarf species and relegates B. saxophila to synonymy. Betula borealis Spach sensu Fernald (1970) is a segregate taxon that if recognized occurs only outside of New York. Gleason and Cronquist (1991) treat this taxon as a hybrid. Furlow (1997) believes the two taxa (B. borealis sensu Fernald and B. minor (Tuckerman) Fern. actually consist of one, somewhat variable, taxon which should be recognized as B. minor. Betula minor was originally described as a variety of Betula papyrifera Marsh. (as B. papyracea Ait.) from the White Mountains of New Hampshire (Furlow and Mitchell 1990). Betula minor has been lumped under the similar B. pubescens by Löve and Löve (1966 in Furlow 1997). Some authors (Hultén 1968 in Furlow 1997, Lepage 1976 in Furlow 1997, Furlow and Mitchell 1990) believe that at least the Adirondack populations which often occur near B. cordifolia and B. glandulosa may have originated by hybridization, perhaps followed by polyploidy, between these two taxa. Gleason and Cronquist (1991) consider B. minor a hybrid of B. glandulosa and "a dwarf alpine form of B. papyrifera" and do not key out this taxon. More work needs to be done to clear up the issues mentioned above (Furlow 1997). Taxonomy Kingdom Phylum Class Plantae Anthophyta Order Dicots (Dicotyledoneae) Family Fagales Betulaceae (Birch Family) NYNHP Conservation Guide - Dwarf White Birch (Betula minor) 4

5 Additional Common Names Dwarf Birch Synonyms Betula alba var. minor ((Tuckerman) Fern.) Betula glandulosa x papyrifera Betula nana x papyrifera Betula papyracea var. minor (Tuckerman) Betula papyrifera var. minor ((Tuckerm.) Wats. & Coult.) Betula pubescens ssp. minor ((Tuckerman) Löve & Löve) Betula pubescens ssp. odorata ((Bechst.) Löve & Löve) Betula saxophila (Lepage) Additional Resources Links USDA Plants Database BETULA+MINOR NatureServe Explorer Google Images References Fernald, M.L Gray's manual of botany. 8th edition. D. Van Nostrand, New York pp. Furlow, J Betulaceae Gray. Pages in Flora of North America Editorial Committee (Editors), Flora of North America, North of Mexico, Volume 3, Magnoliophyta: Magnoliidae and Hamamelidae. Oxford University Press, New York, NY, USA. 590pp + xxiii. Furlow, J.J. and R.S. Mitchell Betulaceae through Cactaceae of New York. New York State Museum Bulletin No The State Education Department, Albany, NY. 93pp+ vi Gleason, Henry A. and A. Cronquist Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp. Holmgren, Noel 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. Keys, Jr.,J.; Carpenter, C.; Hooks, S.; Koenig, F.; McNab, W.H.; Russell, W.;Smith, M.L Ecological units of the eastern United States - first approximation (cd-rom), Atlanta, GA: U.S. Department of Agriculture, Forest Service. GIS coverage in ARCINFO format, selected imagery, and map unit tables. Mitchell, Richard S. and Gordon C. Tucker Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No New York State Museum. Albany, NY. 400 pp. NYNHP Conservation Guide - Dwarf White Birch (Betula minor) 5

6 NatureServe NatureServe Central Databases. Arlington, Virginia. USA New York Natural Heritage Program Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY. Reschke, Carol Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi. Weldy, T. and D. Werier 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, New York New York Natural Heritage Program 625 Broadway, 5th Floor, Albany, NY Phone: (518) This project is made possible with funding from: - New York State Department of Environmental Conservation Hudson River Estuary Program - Division of Lands & Forests, Department of Environmental Conservation - New York State Office of Parks, Recreation and Historic Preservation Information for this guide was last updated on Aug 11, 2017 This guide was authored by NYNHP Conservation Guide - Dwarf White Birch (Betula minor) 6