Platanthera huronensis (Tall Northern Bog Orchid)

Plant Info
Also known as:
Family:Orchidaceae (Orchid)
Life cycle:perennial
Habitat:part shade, shade, sun; bogs, marshes, rocky lakeshores, wet meadows
Bloom season:June - August
Plant height:4 to 40 inches
Wetland Indicator Status:GP: OBL MW: FACW NCNE: FACW
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: irregular Cluster type: raceme Cluster type: spike

[photo of flowers] Long, spike-like raceme of 10 to 60, 3/8-inch irregular flowers. Flower color ranges from pale green to greenish white, the lower lip often whiter than rest of flower. An upper (dorsal) sepal and two lateral petals form a hood above, 2 oval to lanceolate petal-like sepals spread laterally, often curling back at the tips. The lower lip is also lanceolate though more narrowly so than the lateral sepals, and also has a slight to pronounced round dilation at the base. The tip of the lower petal often stays touching the tip of the hood above during the entire bloom period. A tubular, curved spur is behind. Flowers are typically noticeably fragrant.

Leaves and stems: Leaf attachment: alternate Leaf type: simple

[photo of leaves] Leaves are few to several on a single stem, oblong to lance-linear, up to 12 inches long and to 2 inches wide, sheathing the stem, reducing in size as they ascend the stem and becoming bract-like in the upper plant. Stem, leaf surfaces and leaf margins are hairless.


Until recently, in Minnesota Tall Northern Bog Orchid and Northern Green Orchid, (Platanthera aquilonis) were considered to be Platanthera hyperborea, also called Northern Green Orchid but whose range is now considered limited to Greenland and parts of Alaska. There are several easy discriminators between our two species that are helpful when applicable. In Minnesota the range of P. huronensis is restricted to northern boreal forest habitats, its spike can reach nearly 3½ feet in height with up to 60 flowers, and its flowers are typically whitish green and fragrant. It also is a tetraploid species that can occasionally produce incredibly robust specimens (see images) that can have well over 100 flowers on a thick, club-like spike. P. aquilonis is diploid and will never exhibit this trait. While P. aquilonis is found throughout the range of P. huronensis, it also extends across the entire western prairie region where P. huronensis would likely never be encountered (see range maps). It rarely exceeds 2 feet in height with a maximum of 40 flowers and as few as 5, the flowers often conspicuously greenish yellow and without fragrance. Where these characteristics overlap makes field ID a challenge even for experts and requires 10x magnification and a metric ruler. The most precise information for these characteristics can be found in Welby Smith's book “Native Orchids of Minnesota”. For P. huronensis the lower lip is lance-shaped to nearly linear, 4.5-7 mm long by 1.5-3 mm wide, with a slight to pronounced dilation near the base and the anther sacs are borne upright, nearly parallel to one another above the stigma. Also the spur is typically more cylindrical and longer, 4.5-7 mm long. The hood of P. aquilonis also tends to be more flat where P. huronensis is more erect, especially when a flower is in its prime. Flora of North America has a good illustration of these characteristics. The tendency, in many specimens, for the tip of the lower lip to remain adhered to the tips of the upper sepal and petals can make close observation of these traits difficult.

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens
  • Out Back Nursery
  • Shop for native seeds and plants at!

More photos

Photos courtesy Peter M. Dziuk taken ar various locations in Aitkin, Cass, Dakota, Hubbard and Lake counties.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Jim C - Bemidj
on: 2017-06-25 18:58:07

I found this plant in a black ash swamp less than 7 miles outside of Bemidji. I did not have a loupe or a ruler, but it was taller than 24". I'm leaning towards Tall Bog over Green. There were at least a dozen individuals scattered throughout the swamp and mosquitoes appeared to be feeding from them.

Posted by: Elaine E - Cook County, Caribou Trail, in ditch by turnoff to Ward Lake
on: 2017-06-27 14:48:17

Beautiful, healthy, near standing water.

Post a comment

Note: All comments are moderated before posting to keep the spammers out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.