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The Garden Scoop

Eastern Prairie Fringed Orchid

The eastern prairie fringed orchid (Platanthera leucophaea) is perhaps one of the most beautiful native prairie flowers in Illinois.  Its delicately fringed, white flowers gently unfurl from the bottom to the top of its inflorescence over a 7-10 day period during late June and early July in Illinois prairies, but only if conditions are right.  This plant is quite sensitive to annual fluctuations in weather which greatly influences flowering each year.  In good years, up to forty beautiful blooms may adorn flower spikes that reach high into the tip-tops of the prairie to lure in pollinators.  In bad years, this species may not bloom at all, making flowering somewhat of a tricky business.

However, one biologist with US Fish and Wildlife Service is well acquainted with the flowering preferences of this rare prairie species.  Cathy Pollack has been monitoring this species’ populations across its native range closely for many years.  Since 2000, she has been in charge of an initiative by the US Fish and Wildlife Service to restore and preserve populations of this rare plant across several states.

“When I started in 2000 and looked back at the data, I couldn’t see much progress recovering the species in Illinois.” Pollack reflects.

A Recovery Plan was published in 1999 which took a comprehensive look at the species from a historical perspective to the current day across its natural range.  This report determined that the eastern prairie fringed orchid needs 22 viable, healthy populations range-wide to “recover” the species, or stabilize its population to an acceptable level.  Pollack has carefully tracked populations of the orchid over the years to see if recovery efforts are hitting the mark.

“In recent years, I’ve found about 7 to 11 highly viable populations’ across its range and it’s not always the same sites each year,” notes Pollack.

She goes on to explain that there are currently about 90 known populations of the plant but many are not considered viable due to a variety of factors such as the low number of blooming plants, the relatively small size of the prairie or other stresses.  In bad years, many populations will not bloom at all and some may disappear altogether.

Currently, the eastern prairie fringed orchid is considered endangered in Illinois and listed as threatened at the federal level.  One of the primarily reasons for its listing is habitat destruction.  Today the species is primarily, if not exclusively, found in remnant prairies, meaning these sites have remained in prairie plant cover over time, not having experienced a conversion to other land uses in the 1800’s or earlier. 

Remnant prairies are unique in that the native soil ecosystem is still intact, as opposed to reconstructed prairies that may lack some soil biota due to previous land conversion.  This is especially important to the eastern prairie fringed orchid.  It has an exclusive relationship with specialized fungi in the soil, called mycorrhizae, which infect its roots in mutually beneficial relationship. The mycorrhizae must be present to support new orchids during the first few years before they develop productive leaves.  Once established, the orchid returns the favor by suppling the fungi with energy produced by its leaves.

In 2012, Pollack and other experts concluded that something new must be done to recover the species, current measure were not adequate.  With the help of other biologists, natural areas managers and a large group of volunteers around the state, they launched a cross pollination project aimed at boosting the number of viable populations throughout the orchid’s range.

“Our goal is to cross pollinate as much as we can between populations to increase seed production,” says Pollack.

To accomplish that, Pollack and her team of volunteers collect pollen and hand-pollinate orchids around Illinois.  Each year her travels bring her to one population of the eastern prairie fringed orchid that exists in a high-quality, remnant prairie right here in central Illinois.  The site is owned and maintained by the Grand Prairie Friends, a local volunteer-led, not-for-profit conservation organization and land trust that focuses on preservation and restoration of prairie and woodlands in our area.

“Most of what we own and manage is remnant prairie, and as you can see from the numbers, it’s a tiny fraction of the east-central Illinois landscape,” says Jamie Ellis, President of the Grand Prairie Friends Board or Directors. 

In total the group owns about 30 acres of remnant or reconstructed prairie in east-central Illinois. Given the historic loss of prairie in Illinois, today only about 2,000 acres of remnant prairie exist statewide, their “tiny fraction” is an extremely important one for, not only the eastern prairie fringed orchid, but for other rare plant species, not to mention commonly overlooked, but ever important soil biota.