western prairie fringed orchid

EN - Endangered

N3 - Vulnerable

S1 - Critically Imperiled

Endangered

Threatened

Western prairie fringed orchid is a 1′ to 2′ tall, erect, long-lived, perennial forb that rises on a single stem from a tight bundle of fleshy roots.

The stems are stout, erect, and hairless. Flowering stems are usually 18″ to 24″ tall.

The lower leaves are alternate, lance-shaped, ascending, thick, hairless, and 4″ to 10″ long, up to 2″ wide, with a blunt tip. Upper leaves are much smaller.

The inflorescence is loose, open spike at the end of the stem with up to 24 flowers.

The flowers are large, up to 1½″ long, showy, and upside down due to the twisting of the flower stalk. The petals are creamy white. The lower petal (lip) is 3-lobed with a fringed margin. The column is distinctly angular.

1′ to 2′

White

Wet prairies and sedge meadows in the northwest. Moderately moist upland prairies in the southwest.

July

Sources

2, 3, 4, 5, 6, 7, 23, 25, 28, 29, 30, and personal correspondence with the Minnesota Biological Survey.

Some of the sources listed above (2, 3, 5, 6, 28, and , 29) include historical records where no populations currently exist. One source (23) includes a county (Pine) “in which this species is known to or is believed to occur.” Two sources (2 and 30) contain unverified records (Morrison, Ramsey, and Dakota Counties).

In the map at left, counties in dark green include only specimens that have been collected after 1970, deposited in a public herbarium in Minnesota, and verified by an expert. Counties in light green include historical and unverified records.

Public places western prairie fringed orchid can be seen in Minnesota include Blue Mounds State Park; Burnham WMA; Crane Meadows NWR; Felton Prairie SNA, Bicentennial Unit; Iron Horse Prairie SNA; Lake Bronson Parkland SNA; Northern Tallgrass Prairie NWR, Touch the Sky Prairie Unit; Pembina Trail Preserve SNA, Pembina Trail Unit; Pipestone National Monument; and Ulen WMA.

Native

Rare

Western prairie fringed orchid is endemic to tallgrass prairie. There are only 175 known populations in 40 counties in six states and one Canadian province. One quarter of those occurrences are protected by federal, state, or private preserves. Only three large populations have been found: one in Polk County in northern Minnesota, one in eastern North Dakota, and one in Manitoba. A large population may have over 2,000 individual plants. According to Minnesota State Botanist Welby Smith, “…this is Minnesota’s rarest orchid.”