Enchanter’s Nightshade

Enchanter’s Nightshade (Circaea canadensis), also called Broadleaf Enchanter’s Nightshade, is a small but eye-catching perennial that blooms in early to mid-summer along forest trails. Where I live and play in central New Jersey and Pennsylvania, that means late June through mid-July.

Enchanter’s Nightshade (Circaea canadensis)

This diminutive resident of the forest floor has several pairs of leaves opposite each other along the stem, with a cluster of tiny flowers rising above them. It often grows to about a foot (.4 m), but can reach as much as two feet (.7 m) in height, including the flower cluster (infloresence). The tiny white flowers are only about an eighth of an inch (4 mm) in diameter, and yet in the dim light of summer in the woods they are attention-grabbing, for both humans and pollinators.

Enchanter’s Nightshade (Circaea canadensis)

Each flower has two deeply lobed white petals that look a little like mouse ears, backed by two green, wing-shaped sepals that protected the flower before it opened. Two stamens, the male reproductive parts, reach out like arms from each side at the center of the flower, the anthers at their tips resembling mittened hands. The long narrow structure projecting from the very center of the flower is the pistil, the female reproductive part.  The circular washer-shaped tissue at the base of the pistil is the source of the flower’s nectar, which is offered to entice pollinators to visit.

Enchanter’s Nightshade (Circaea canadensis) flower, with 2 deeply-lobed white petals, 2 stamens reaching out like arms, and one pistil in the center with a circular nectary at its base.

In profile it’s easy to see the veining on the flower’s petals. They are nectar guides, directing pollinators to a potential reward inside.  The stigma reaches out beyond the petals, ready to accept incoming pollen on the stigma at its tip, positioned to be the first thing a pollinator encounters when visiting. The flower’s ovary, covered in hooked hairs, is visible behind the sepals. If pollination is successful, this will ripen to become a small burr-like fruit.

Enchanter’s Nightshade (Circaea canadensis) flower. Notice the veins that act as nectar guides on the petals, the pistil extending beyond the petals, and the hairy ovary behind the green sepals.

The stems of the entire inflorescence are covered with glandular hairs. Hairs on plant tissue usually serve to discourage herbivores from eating the plant, and glandular hairs often have the added benefit of emitting a chemical offense to enhance the deterrent effect.    

Enchanter’s Nightshade (Circaea canadensis) inflorescence. Note that in addition to the flower ovaries, the main stem and flower pedicels (stems) are all covered with glandular hairs, a deterrent to herbivores.

Even such tiny flowers have pollinators who are perfectly matched for them, primarily sweat bees (Halictidae) in the genus Lasioglossum and tiny flower flies, most commonly of the species Toxomerous geminatus. The group of bees called sweat bees get this common name from their habit of obtaining nutrients by licking up human sweat.

Enchanter’s Nightshade (Circaea canadensis) inflorescence, with a sweat bee visiting a flower near the top, and a flower fly perched at the tip of the branch in the lower right.

The bees visit the flowers for both nectar and pollen.  The little sweat bee in the photo below is feeding herself, but also gathering pollen, visible on her hind legs, to bring back to her nest for her larvae. 

Sweat bee, Lasioglossum species, visiting Enchanter’s Nightshade (Circaea canadensis) flower for nectar and pollen. Notice the pollen on her hind legs, which she will bring back to her nest to feed her larvae.
Sweat bee, Lasioglossum species, harvesting pollen from the anther at the tip of the stamen of an Enchanter’s Nightshade (Circaea canadensis) flower

On several occasions, I have watched small swarms of tiny flower flies hovering around Enchanter’s Nightshade flowers.  ‘Hover fly’ is another common name for this group of insects, because of their ability to perform this maneuver. Any individual I was able to see well enough to identify was a Toxomerous geminatus

A flower fly, Toxomerus geminatus, hovering near an Enchanter’s Nightshade (Circaea canadensis) inflorescence

Like the bees, the flies visit the flowers for both nectar and pollen, both of which are important food sources for them.

A flower fly, Toxomerus geminatus, harvesting pollen from an Enchanter’s Nightshade (Circaea canadensis) flower. As it first approached the flower, it came in contact with the stigma at the tip of the pistil, the female reproductive part, before moving on to harvest pollen.
Toxomerus geminatus at rest on a nearby leaf.

After pollination, the flower’s petals, sepals, stamens and pistils wither and fall away, leaving the ovary to ripen to a fruit.

The ovary of an Enchanter’s Nightshade (Circaea canadensis) flower, after its petals, sepals, stamens and pistils have withered and fallen off

As the ovary matures to a fruit, the hooked hairs covering the fruit stiffen, becoming an effective mechanism to grab on to the fur or pants of a passing animal who then unknowingly helps to disperse the seeds. 

Enchanter’s Nightshade (Circaea canadensis) inflorescence with many mature fruits positioned to hitch a ride on the fur or pants of a passing animal.

Enchanter’s Nightshade also has the ability to reproduce through its underground parts, sending up additional shoots to form colonies. 

Why the name Enchanter’s Nightshade?  The Greek goddess and accomplished enchantress Circe reportedly often used potions and herbs to achieve her ends, sometimes turning enemies into other animal species. Plants in this genus, Circaea, were thought to be among the ingredients she used, so were named for her. So far, unfortunately, I haven’t found any of her recipes.   

Enchanter’s Nightshade can be found along forest trails in the United States from Maine west to North Dakota, south as far as Oklahoma, Louisiana, and Georgia, and in Canada from Quebec and Nova Scotia west to Manitoba.  

Take a cooling summer walk in the woods to look for Enchanter’s Nightshade and its pollinators.

Small Enchanter’s Nightshade (Circaea canadensis) colony

Note:  Some sources refer to this species as Circaea lutetiana, Circaea lutetiana L. ssp. canadensis, or Circaea  quadrisulcata.

Resources

Boufford, David E. “The Systematics and Evolution of Circaea (Onagraceae).” Annals of the Missouri Botanical Garden, vol. 69, no. 4, 1982, pp. 804–994. JSTOR,

Global Biodiversity Information Facility (GBIF)

Illinois Wildflowers

Minnesota Seasons.com

Minnesota Wildflowers, copy and paste: https://www.minnesotawildflowers.info/flower/enchanters-nightshade

Niering, William A. The Audubon Field Guide to North American Wildflowers, Eastern Region. 1979.

USDA NRCS Plants Database

Wikipedia

Zakaria Hazzoumi, Youssef Moustakime and Khalid Amrani Joutei (June 24th 2019). Essential Oil and Glandular Hairs: Diversity and Roles, Essential Oils – Oils of Nature, Hany A. El-Shemy, IntechOpen, DOI: 10.5772/intechopen.86571.

22 thoughts on “Enchanter’s Nightshade

  1. Mary Anne, Thank you so much for this wonderful post and the stunning photos. Just yesterday I saw this flower in the woods for the first time, and identified it last night at home. Then just today I caught up with your blog post! Serendipity, and joy. Your post made me appreciate its beauty and complexity even more.

  2. One of the few unassuming flowers I remember, because the common name is so charming. And they do get a bit bold in your garden if you let them. Thank you for reminding me of their beauty.

  3. I find this species and its smaller cousin Alpine Enchanter’s Nightshade (Circaea alpina) here in Baileys Harbor WI. C. alpina seems to be the more common of the two here.

  4. These are growing around my front porch nestled in among some boxwood and spruce. Was wondering what they were but never got around to looking them up. Thanks.

  5. Hi Maryanne,

    Same as Bernie, I know this plant but didn’t realize the special features you pointed us to. I love the photos of the bees and the hairy flower parts. Fascinating. Heading out soon to check them out with the respect they deserve. Thanks as ever.

  6. Thank you Mary Anne for another wonderfully interesting and educational blog post. Your spectacular photos are a treat and a lesson in themselves, as they always capture the essence of your written blog.
    Cheers,
    Michael O’Brien

  7. Mary Anne, thanks bunches for your post. This is a flower that I’m a tiny bit familiar with but have (in the past) chosen to not give it much attention. Thank you for opening my eyes. Interesting descriptions to read, and your photos are lovely. Bren

  8. Capturing great photos of objects the size of Enchanter Nightshade flowers and fruits is incredibly demanding. Doing so in the field is even more difficult. Doing so in a forest increases that difficulty exponentially. Capturing excellent images of insects on the wing visiting those forest flowers demands a level of difficulty that is frankly incalculable. I’m awed by this blog.

Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.