Heart-leaved twayblade, Listera cordata
Once thought lost, rare orchid reappears in Ohio
May 31, 2015
The orchid family is gargantuan, with an estimated 22,000 species. It is thought to be the second-largest flowering plant family, barely bested by the sunflower family.
Orchids reach their peak in tropical climates, which Ohio is decidedly not. The Buckeye State hosts a mere 46 native species (and one weedy non-native, the helleborine).
Most of our orchids are finicky specialists. Many species are wedded to rare habitats such as bogs, fens and wet prairies. Changes to the landscape after European settlement have not been kind to orchids (or most of our 1,800-plus species of native plants).
In total, 22 orchid species are listed as endangered, threatened or potentially threatened. Another four are considered extirpated, or locally extinct. Extirpated species occur elsewhere but have not been seen in Ohio for at least 20 years.
When an extirpated plant is rediscovered, it’s major news in the botanical world. Thus, May 26, 2013, was a big day for Lake Metroparks biologist John Pogacnik and son Shaun. They had bushwhacked deep into Ashtabula County’s Morgan Swamp, a wild land owned by the Nature Conservancy.
While exploring the swampy ground, overshadowed by towering hemlock and yellow birch, the Pogacniks noticed a tiny, unfamiliar plant.
They had stumbled into a colony of heart-leaved twayblade (Listera cordata). This miniscule orchid had been found only once before, in 1933, also in Ashtabula County. It was a holy grail plant for field botanists. Because of the find, the orchid moved from the extirpated to the endangered category.
One can literally traipse through a twayblade colony and miss the plants. A whopper might rise 4 inches above the shady forest floor. Many specimens are only an inch or two tall. The ornate flowers are charming upon close inspection but aren’t much bigger than a mosquito.
Orchids are notorious for their booms and busts. Last year, few twayblades appeared aboveground. This year, several hundred burst forth. Pogacnik took me to the site on May 17, and the plants were at the zenith of their glory.
Heart-leaved twayblade occurs in cool habitats throughout the upper reaches of the Northern Hemisphere. It was first described as Ophrys cordata by Swedish naturalist Carl Linnaeus in 1753.
In 1813, Scottish botanist Robert Brown placed it in the genus Listera, which he coined in honor of the great English naturalist Martin Lister. Not coincidentally, Brown helped pioneer the use of powerful microscopes. High magnification is necessary to see minute details of Listera blossoms.
Kudos to the Nature Conservancy for protecting Morgan Swamp. It is a crown jewel of Ohio natural areas and harbors many rare species. I’m sure the 1,400-acre forested wetland still holds secrets.
For more information on the Nature Conservancy in Ohio, visit www.nature.org/Ohio.
Naturalist Jim McCormac writes a column for The Dispatch on the first and third Sundays of the month. He also writes about nature at www.jim mccormac.blogspot.com.