Listera auriculata (Auricled Twayblade)
|Also known as:|
|Habitat:||part shade, shade; acidic, sandy, alluvial soil, mossy banks, hardwood forest along streams, under alders, rocky shore of Lake Superior|
|Bloom season:||June - July|
|Plant height:||4 to 8 inches|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Loose raceme of 5 to 20 stalked, irregular flowers at the tip of the stem. Flowers are ¼ to 1/3 inch long, pale green, with a short, curved central column and a lower lip that is more or less oblong but slightly broader at the tip end, often translucent around the edges and notched up to 1/3 its length, the 2 lobes broadly rounded at the tip. At the base of the lower lip is a pair of narrow lobes (auricles) that curve around the back of the column. The lateral petals and sepals are about 1/8 inch long. linear to lance-elliptic, curving to a pointed tip; the upper petal curls back away from the column. Flower stalks are covered in glandular hairs.
Leaves and stems:
A single pair of stalkless, opposite leaves sits about halfway up the stem. Leaves are 1 to 2¼ inches long, 2/3 to 1½ inches wide, toothless, hairless, egg-shaped to oval or nearly round with a blunt or softly pointed tip. The stem is green and glandular hairy above the leaves, smooth below.
This is indeed a rare one, with only a handful of sightings in Minnesota during the last 100 years or so, and it is equally as rare throughout most of its range. Typically found in the sediment or mossy banks of cool streams in hardwood or mixed forests (often under alders), in Minnesota it also populates the rocky shore of Lake Superior. According to the DNR, it was listed as a State Endangered species in 1996 due to its few locations, low populations, the threats of high water levels (man-made or natural) causing habitat destruction, and the fact that it does not seem to persist long at any one location. Most of the populations indicated by herbarium records no longer exist so it was indeed a once-in-a-lifetime event for us to stumble upon it along the north shore of Lake Superior in Cook County, and a significant population at that. While the leaves are similar to Heart-leaved Twayblade (Listera cordata), the flowers are easily distinguishable, with L. cordata having a narrow lower lip that is forked like a snake's tongue. Even more rare is the similar Broad-leaved Twayblade (Listera convallarioides), which has flowers with a lower lip that is not auricled or notched at the tip. L. auriculata is also sometimes known as Neottia auriculata.
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Where to buy native seed and plants ↓
- Auricled Twayblade plants
- Auricled Twayblade habitat
- Auricled Twayblade in a rock crevice
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Photos by K. Chayka and Peter M. Dziuk taken in Cook County.
Have you seen this plant in Minnesota, or have any other comments about it?