Select plants, fungi, and algae found in the county
The flora of Door County, Wisconsin comprise a variety of plant species. Geobotanically, Door County belongs to the North American Atlantic Region.
Plant species lists As of 2019, 1201 species and hybrids of vascular plants have been identified in the county,Wisflora Species list including the yellow lady's-slipper Cypripedium parviflorum, the official county flower.Green Fund: Friends and Donors, archived October 2, 2011. 255 unique taxa of mosses, liverworts, and hornworts have been identified in Door County.
Islands In 2001, species lists were compiled for the county's islands. Snake Island had 156 species, Cana Island had 111, Hat Island 22, Chambers Island 398, Adventure Island 58, Little Strawberry Island 44, Jack Island 28, Horseshoe Island 49, Sister Island 6, Spider Island 42, Plum Island 259, Detroit Island 25, Pilot Island 40, Washington Island 626, Hog Island 34, Rock Island 333, and Gravel and Fish islands were devoid of plant life.Flora and vegetation of the Grand Traverse Islands (Lake Michigan), Wisconsin and Michigan by Judziewicz, EJ., The Michigan Botanist, Vol. 40. 2001, p. 85 In particular, Washington Island is one of only two places in Wisconsin where the fern Asplenium viride (green spleenwort) is found.Conservation Assessment for Green Spleenwort (Asplenium trichomanes-ramosum) L by the USDA Forest Service, Eastern Region, March 2002, subsection "Habitat and Ecology, p. 9
Lakes In 2006, 60 species of aquatic plants or macrophytic algae were found in Clark Lake and nearby upstream, including spotted pondweed, Potamogeton pulcher, which is endangered in Wisconsin.Potamogeton pulcher Tuck. spotted pondweed, USDA PLANTS database, Accessed December 13, 2019 In 2017, 9 species of aquatic plants were found in the Forestville Millpond, also called the Forestville Dam or Forestville Flowage.
Rare plants Along with nearby Marinette and Delta (see Garden Peninsula) counties, Door County is home to endemic plants and disjunct populations, such as those protected at Plum Island, Coffee Swamp, Cave Point County Park, the adjacent Whitefish Dunes State Park, and The Ridges Sanctuary. The Grand Traverse islands have some of Wisconsin's richest rare plant reserves.A Guide to Significant Wildlife Habitat and Natural Areas Of Door County, Wisconsin, March, 2003, by the Wisconsin Department of Natural Resources Sturgeon Bay Service Center, p. 128, p. 52, p. 23, p. 127 and pp. 52, 83, 85, and 99 (note: pagination in the pdf is one page past the numerical pagination)
Invasive species In 2019, 25 miles of roadsides were surveyed for invasive species,County of Door 2019 Annual Reports, page 70 and in 2020, 62 miles of streams were surveyed for invasive species.County of Door 2020 Annual Reports, page 73 A county-wide electronic map of Japanese knotweed, Phragmites, teasel, and wild parsnip infested locations is updated annually.Web-Map of Door County, Wisconsin ... For All Seasons! , Door County Land Information Office, Accessed September 7th, 2019 Locations of other problem species have also been documented.Priority Invasive Species Lists in Wisconsin, electronic map
Plant communities unique to the area The county is home to a variety of plant communities, including some unique to the area. Boreal rich fen is called "rich" because the dolomite makes the soil more fertile.Boreal rich fen, Detailed Community Description from Ecological Landscapes of Wisconsin General natural community overview, Wisconsin DNR, accessed September 9th, 2019 Calcicole plants growing in these fens depend on minerals which the dolomite contributes to the soil.Biodiversity Investment Areas: Coastal Wetland Ecosystems by Patricia Chow-Fraser and Dennis A. Albert, State of the Lakes Ecosystem Conference 1998, July 1999, Table 5.6 Lake Michigan shoreline reaches and their characteristic wetlands, p. 46 (p. 51 of the pdf) The southernmost boreal forests in the state are on the eastern side of the peninsula.Boreal forest, Detailed Community Description from Ecological Landscapes of Wisconsin General natural community overview, Wisconsin DNR, accessed January 20, 2020. In white cedar variant forests, white cedar coexists with hardwoods and balsam fir in upland stands that ordinarily would not support cedar. This forest cover is likely due to the alkaline soil and mostly grows on the Niagara Escarpment along the Green Bay side of the peninsula or near the Lake Michigan shoreline. A combination of high humidity, high levels of calcium and magnesium carbonates from the dolomite, and weathered, nutrient poor soils are thought to limit microbial activity. As a result, a layer of humus builds up from organic matter falling to the ground.The Origins and Properties of Alkaline Raw Humus by Harry Merrill Galloway, MS thesis, UW-Wisconsin, 1938 The escarpment also features the dry cliff natural communityDry cliff, Detailed Community Description from Ecological Landscapes of Wisconsin General natural community overview, Wisconsin DNR, accessed September 10th, 2019 and is home to two rare species of whitlow grass.Hoary Whitlow-grass (Draba cana), Wisconsin DNR, accessed September 10th, 2019Rock Whitlow-grass (Draba arabisans), Wisconsin DNR, accessed September 10th, 2019 Other uncommon communities are alvar and the similar Great Lakes alkaline rockshore,Alvar, Detailed Community Description from Ecological Landscapes of Wisconsin General natural community overview, Wisconsin DNR, accessed September 9th, 2019.Great Lakes alkaline rockshore, Detailed Community Description from Ecological Landscapes of Wisconsin General natural community overview, Wisconsin DNR, accessed September 9th, 2019 also home to rare plants.
Vegetation along the Green Bay and Lake Michigan shores
Yearly fluctuations in lake levels alternately kill off vegetation during periods of high water and promote succession during times of low water. Even during times of high water when low-lying plants are inundated, the populations may persist uphill by clonal expansion and spreading their seeds. Lake Michigan has more diverse shoreline vegetation than Lake Ontario, which has a more stable water level due to human intervention. Without the changing lake levels the shoreline would be dominated by woody plants or highly competitive and even invasive water-loving species such as cattails, reed canary grass, or purple loosestrife. Wet meadows like this one thrive when flooding does not occur often enough to allow emergent vegetation to prevail but is still too frequent to allow the establishment of trees and shrubs.p. 828 of Hydrogeomorphic Factors and Ecosystem Responses in Coastal Wetlands of the Great Lakes by Janet R. Keough, Todd A. Thompson, Glenn R. Guntenspergen, and Douglas A. Wilcox, December 1999, Environmental Science and Ecology Faculty Publications Vol. 51
Out of miles of county shoreline along Lake Michigan and Green Bay surveyed in 2012, was vegetated with of high density shrubs and trees. There was also of low density shrubs and trees, of moderate density shrubs and trees, of unmaintained herbaceous vegetation, of manicured lawns, and with no vegetation.
Individual trees Some trees have attracted attention: One white cedar found on the escarpment was over 600 years old and near other old-growth cedars.Door County Comprehensive Forest Plan, completed about 2008, see also for reference the map of all Door county woodlands The largest tree in the county is a 170-year-old eastern cottonwood on the west side of Highway 57 passing through Institute. It is 110 feet tall and 35 feet in circumference.Door County Coastal Byway Interpretive Master Plan by Schmeeckle Reserve Interpreters, p. 25, (p. 30 of the pdf), 2014 In 1997, striped maple was discovered in a shoreline forest near Newport, the first time this species was documented in the state.Chapter 15, Northern Lake Michigan Coastal Ecological Landscape. from The ecological landscapes of Wisconsin: An assessment of ecological resources and a guide to planning sustainable management. Madison: Wisconsin Department of Natural Resources, 2015. PUB-SS-1131Q 2015, p. Q-23 (p. 33 of the pdf) In 1969, Franklin Gilbert introduced the Viking apple, an early Macintosh moderately resistant to apple scab and fireblight.Growing Fruit in the Upper Midwest by Don Gordon, University of Minnesota Press: Minneapolis, 1991, p. 47History of the Department of Horticulture, Chronology of the Department’s Research Highlights and Growth, University of Wisconsin Madison, 2014, p. 16 The original Viking tree is exhibited to the public at the Peninsular Research Station. In 1971, a paper birch was found on Detroit Island. At five and a half feet the trunk diameter was thirty-six and six-tenths inches and the circumference was nine and a half feet. Its height was sixty-five feet and its average crown spread was fifty-nine feet.Detroit island's birch survived the centuries by Roy Lukes, Door County Advocate, March 4th, 1971 In 2005, the state record Lombardy Poplar grew in Ephraim.Wisconsin's Champion Trees: A Tree Hunter's Guide by R. Bruce Allison, 2005, Wisconsin Book Pub. As of 2013, a notable Sugar Maple grew in Sturgeon Bay or to the south of Sturgeon Bay. It had a circumference of 200 inches and a height of 86 feet. As of 2013, a Red Oak grew in a cemetery several miles south of Egg Harbor along Highway 42 and had a circumference of 146 inches. As of 2013, a White Oak near the county border had a circumference of 149 inches and its height was 86 feet. In 1947, a white pine on Washington Island was estimated to be 400 years old.400-Year Pine on Island; Towering Elm, Egg Harbor , Door County Advocate, Volume 86, Number 22, page 1 As of 2013, an American Elm along the Ahnapee Trail had a circumference of 180 inches. In 1952, an elm in Egg Harbor had the second-largest girth in the state.Giant Egg Harbor Elm Can lay Claim to Championship , Door County Advocate, Volume 91, Number 47, July 24, 1952, page 1 and Reign of Jorns Elm Ended by Madison Conservationist , Door County Advocate, Volume 91, Number 53, September 18, 1952, page 2 As of 2013, a 90-foot-tall American Beech grew in the White Cliff Fen.Champion Trees of Door County by Roy and Charlotte Lukes, November 21, 2013, doorcountypulse.com
Macrofungi species lists As of 2019, 243 species of mushrooms and other macrofungi have been identified north of the canal, with 326 species for the county as a whole, including those found in lichens. Several of the more uncommon lichens found in the county are Cetraria arenaria, which grows on the ground,Lichens: Alluring but Little-Known Plants by Roy and Charlotte Lukes, Peninsula Pulse, November 21st, 2011 and Anaptychia crinalis, which grows on tree bark.Hanging Fringed Lichen (Anaptychia crinalis), Wisconsin DNR, accessed September 10th, 2019
Hybrid yeast In 2009, a unique hybrid of Saccharomyces cerevisiae yeast was found on fallen cherries near Fish Creek. This strain of S. cerevisiae descended from both oak-tree and vineyard lineages.
Spongy moth fungus In 1910, Entomophaga maimaiga from Japan was released in Boston in order to infect spongy moths and control their population.The Gypsy Moth Fungus Entomophaga maimaiga in North America by Richard C. Reardon and Ann E. Hajek, US Forest Service, Forest Health Technology Enterprise Team, June, 1998, page 19 (page 23 of the pdf) In 1996, it was discovered that E. maimaiga had naturally spread to southern Door County. This was the first time it had been detected in the state.Inoculative Releases and Natural Spread of the Fungal Pathogen Entomophaga maimaiga (Entomophthorales: Entomophthoraceae) into U.S. Populations of Gypsy Moth, Lymantria dispar (Lepidoptera: Erebidae), by Ann E. Hajek, Andrea L. Diss-Torrance, Nathan W. Siegert, and Andrew M. Liebhold, Environmental Entomology, June 15, 2021, pages 5–6
See also Flora of the United States Great Lakes § Flora List of Michigan flowers