Extinct Plants of northern North America 2020

As in past years, I'm limiting this list to northern North America for two reasons:

1. Restricting this list geographically is in keeping with my specialization in plants native to northeastern North America.
2. There are many more tropical plants, and plant extinctions, than I can manage.

In past years, I've only been able to find records for 6 plant species that have gone extinct. This year's list is a major update: 59 extinctions, and 7 extinct in the wild. This is largely due to the research presented in this August 2020 paper:

Vascular plant extinction in the continental United States and Canada

The summary is terse, and grim:

Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here.

Note that they only examined vascular plants. So their list excludes Neomacounia nitida, Macoun's shining moss. It remains on the full list, below.

Because of the large number of added species, and sun-species taxa, I've highlighted those from past years with an asterisk *. Everything else I added this year. If you have additions or corrections to this list, please let me know, and provide a link which I can research.

Extinct

• Agalinis caddoensis, Railroad near Shreveport, Louisiana. last observed 1913
• * Astilbe crenatiloba, Roan Mountain false goat's beard, Roan Mountain, Tennessee, 1885
• Astragalus endopterus, near Cameron, Coconino County, Arizona. Last observed 1947
• Astragalus kentrophyta var. douglasii, Washington/Oregon?, 1883
• Astragalus robbinsii var. robbinsii, Vermont, 1894
• Atriplex tularensis, California, 1891
• Blephilia hirsuta var. glabrata, Manchester, Bennington County, ermont, 1932
• Boechera fruticosa, Yellowstone, Wyoming, 1899
• Brickellia chenopodina, Grant County, New Mexico, 1903
• Brickellia hinckleyi var. terlinguensis, Brewster County, Texas, 1937
• Calochortus indecorus, Sexton Mountain, Josephine County, Oregon, 1948
• Calochortus monanthus, Yreka, Siskiyou County, California, 1876
• Calystegia seium ssp. binghamiae, Santa Barbara, California
• Castilleja leschkeana, Point Reyes, Marin County, California, 1947
• Castilleja uliginosa, Pitkin Marsh, Sonoma County, California, 1984
• Cirsium praeteriens, Palo Alto, Santa Clara County, California, 1901
• Corispermum pallidum, Washington, 1931
• Crataegus austromontana, Sand Mountain region and Cumberland Mountains, Alabama and Tennessee, 1916
• Cryptantha aptera, Grand Junctino, mesa County Colorado, 1892
• Cryptantha hooveri, California, 1939
• Cryptantha insolita, north of Las Vegas, Nevada, 1942
• Dalea sabinalis, Texas, 1950s
• Digitaria filiformis var. laeviglumis, Hillsboro County, NH, 1931
• Diplacus traskiae, near Avalon, Santa Catalina Island, California, 1901
• Eleocharis brachycarpa, Tamaulipas, Mexico (1959) and Texas, 1834
• Elodea schweinitzii, New York and Pennsylvania, 1832
• Erigeron mariposanus, California, 1900
• Eriochloa michauxii var. simpsonii, Florida, 1966
• Govenia floridana, Miami-Dade County, Florida, 1964
• Hedeoma pilosa, Old Blue Mountain, Brewster County, Texas, 1940
• Helianthus nuttallii ssp. parishii, Orange County, California, 1937
• Helianthus praetermissus, Arizona (likely) or New Mexico, 1851
• Isocoma humilis, Washington County, Utah, 1971
• Juncus pervetus, Lewis Bay, West Yarmouth, Barnstable County, Massachusetts, 1927
• Lechea lakelae, Collier County, Florida, 1987
• Lycium verrucosum, Arroyo Cliffs, San Nicolas County, California, 1901
• Marshallia grandiflora, North Carolina, 1919
• Micranthemum micranthemoides, Mid-atlantic United States, 1941
• Monardella leucocephala, California, 1941
• Monardella pringlei, San Bernardino County, California, 1941
• * Narthecium montanum, Appalachian Yellow Asphodel, East Flat Rock Bog, Henderson County, North Carolina, 1919
• * Neomacounia nitida, Macoun's shining moss, Belleville, Ontario, 1864
• * Orbexilum macrophyllum, bigleaf scurfpea, Polk County, North Carolina, 1899
• * Orbexilum stipulatum, large-stipule leather-root, Falls-of-the-Ohio scurfpea, Rock Island, Falls of the Ohio, KY, 1881
• Paronychia maccartii, Rio Grande Plains, Webb County, Texas, 1962
• Plagiobothrys lamprocarpus, Grants Pass, Josephine County, Oregon, 1921
• Plagiobothrys lithocaryus, Mayacamas Mountains, California, 1899
• Plagiobothrys mollis var. vestitus, Petaluma, Sonoma County, California, 1880
• Polygonatum biflorum var. melleum, Lake St. Clair, north of Detroit, Michigan and Windsor, Ontario, 1937
• Potentilla multijuga, South Coast Ballona Marsh, Los Angeles County, California, 1893
• Potentilla uliginosa, Cunningham Marsh, Sonoma County, California, 1947
• Proboscidea spicata, Rio Grande, Texas, 1967
• Quercus tardifolia, Chisos Mountains, Brewster County, Texas, 2007
• Ribes divaricatum var. parishii, California, 1980
• Rumex tomentellus, Willow Creek, Mogollon Mountains, Catron County, New Mexico, 1954
• Sesuvium trianthemoides, Kenedy County, Texas, 1947
• Sphaeralcea procera, Deming, Luna County, New Mexico, 1943
• Tephrosia angustissima var. angustissima, Pine Rocklands, Florida, 1947 (1985?)
• * Thismia americana, banded trinity, Lake Calumet, Cook County, Illinois, 1916

Extinct in the wild (IUCN Red List code EW)

• Arctostaphylos franciscana, Central Coast, San Francisco County, California. Last observed in the wild 2009
• Crataegus delawarensis, Delaware, 1903
• Crataegus fecunda, Arkansas, Illinois, Kentucky, Missouri, 1930s
• Crataegus lanuginosa, Webb City, Jasper County, Missouri, 1957
• Euonymous atropurpurea var. cheatumii, Dallas County, Texas, 1944
• * Franklinia alatamaha, Franklin Tree
• Prunus maritima var. gravesii, beach plum, groton, New London County, Connecticut, 2000

Related Content

Grief and Gardening: Ashes (Remembrance Day for Lost Species), 2019-12-02

Extinct Plants of northern North America 2018, 2018-11-30

Extinct Plants of northern North America 2015, 2015-11-29
Extinct Plants of northern North America, 2014-11-30

Links

Vascular plant extinction in the continental United States and Canada, 2020-08-20, Authors: Wesley M. Knapp, Anne Frances, Reed Noss, Robert F. C. Naczi, Alan Weakley, George D. Gann, Bruce G. Baldwin, James Miller, Patrick McIntyre, Brent D. Mishler, Gerry Moore, Richard G. Olmstead, Anna Strong, Kathryn Kennedy, Bonnie Heidel, Daniel Gluesenkamp

Wikipedia: List of extinct plants: Americas
IUCN Red List: List of species extinct in the wild
Extinct and Extirpated Plants from Oregon (PDF, 5 pp)