mesic forests, grow a regal group of North American plants, the rein orchis, or fringed orchids. Fringed orchids found in the United States are members of the genus Platanthera and have more than 500 tropical relatives worldwide. Eight species are known to have occurred historically in Missouri and most are in a perilous state, mainly due to habitat changes.
With local names such as soldier’s plume, frogspike, ragged orchid, prairie fringed orchid and pride-of-the peak, it is clear that this assemblage of orchids is not your average daisy or run-of-the-mill rose. And while each species is unique, they share a few common characteristics. Arising from tuberous roots, the smooth stem usually supports two to eight leaves and is topped with a spike covered with several fragrant and sometimes brightly colored individual flowers. The lower lip may be entire or fringed and has a long spur-like appendage that extends downward. For all of these orchids, summer is their time to shine, with June, July, August and September being the best months to look for them in their preferred habitats.
Two of our native species, Platanthera praeclara, the western prairie fringed orchid, and Platanthera leucophaea, the eastern prairie fringed orchid, are currently listed as threatened under the U.S. Endangered Species Act. Due to invasive vegetation and land development activities these species have been pushed out of their native range, and sightings in Missouri are extremely rare. Interestingly, both western and eastern prairie fringed orchids are pollinated at night by sphinx moths, and thus depend upon these nocturnal insects for their survival.
Rarely encountered, Missouri’s pogonia orchids enjoy the seclusion of rich Ozark woodlands, fens and stream valleys. Remaining underground for several years without flowering, large and small whorled pogonias, Isotria verticillata, and Isotria medeoloides, have yellowish-green flowers and are observed far less frequently than the fragile white nodding pogonia, Triphora trianthophora. In fact, the small whorled pogonia is so rare that it has been documented only once in Missouri during the late 1800s from a single location in Bollinger County. The rose pogonia, Pogonia ophioglossoides, has only been viewed in Shannon and Reynolds counties.
As summer gives way to autumn, many wildflowers fade and wither, but for a complex group of small orchids, the late summer into fall transition is a time to shine. Six out of the seven species of Spiranthes, also known as ladies’ tresses or pearl twist orchids, find their seasonal niche amongst the towering yellow blades of prairie and glade grasses and browning coneflower seed heads, as well as within low-lying wet meadow swales and Ozark fens. Although their preferred habitats may be readily distinguishable, the flowers themselves are hard to identify without use of a hand lens and your nose.
While August through early November signals the peak blooming period for nearly all Missouri Spiranthes, yellow-lipped ladies’ tresses orchid, Spiranthes lucida, may be found around bluffs and wet fields within the Ozarks during spring. Like other pearl twist species, this small flower showcases a spike of small, white, tubular-shaped flowers. When one of its individual flowers is viewed up close, however, a bright yellowish-orange spot can be seen on its square-shaped lip.
The autumn-blooming ladies’ tresses require a more scientific approach for identification, based primarily upon leaf shape, distinctive odor, or lack there of, and the twist of their floral structure. All seven species appear to be found more within counties south of the Missouri River.
Arriving with autumn’s chilly temperatures and falling leaves are late coral roots, Corallorhiza odontorhiza, which, along with their spring-blooming relative spring coral root, Corallorhiza wisteriana, may be found in both southern and northern Missouri. Coral root orchids are colonial in nature and frequently consist of 10 or more plants per colony. Both early and late coral roots, as well as the crested coral root, Hexalectris spicata, are saprophytic and lack chlorophyll. Therefore, they rely entirely upon mycorrhizal fungi for all of their nutrients.
Worldwide many orchids are threatened, and Missouri species are no exception. The Missouri Species and Communities of Conservation Concern checklist lists nearly half of the state’s species as critically imperiled or, in some cases, extirpated.
Habitat disturbance, invasive vegetation competition and illegal digging and over-collection place many plant populations in jeopardy. Orchids collected in the wild have a poor chance of survival. Protection of habitat and leaving existing populations intact provide the best overall chance of these unique plants remaining a part of our native flora and for future generations to view the tropical side of Missouri.