The Weedy Orchid Helleborine

Broad-leaved Helleborine (Epipactis helleborine)

Helleborine 🔈 (Epipactis helleborine) is a weedy orchid that has been making it’s appearance more and more in home lawns and gardens. It’s ability to sprout from any small fragment of it’s rhizomes, left in the ground, makes it a very difficult plant to weed out or eradicate; especially considering these rhizomes can be deeply established. This coupled with it’s dust like seeds that can easily spread on the wind give this orchid the potential, in the right setting, to become quite invasive. Although it still is available in e-commerce, it usually comes with a warning.

Identification of Helleborine

Over-all growth habit: Broad-leaved Helleborine is a perennial that grows up to 36″ tall. Their stem is fairly sturdy and more than one stem can arise from the root stock.

Leaves: are mid-green in colour, lanceolate to ovate in shape measuring up to 6″ long by 3″ wide with smooth edges, a pointed tip and parallel veins that give them a ribbed appearance. The leaves alternate up the stem, with wide spaces between them, getting progressively smaller as they rise up the stem. They are stalkless and tend to clasp the stem.

Stems: are erect, fairly sturdy, green (may be purplish in colour towards the base), hairy (especially towards the top) and measure between 30 and 90cm (1′ to 3′) tall.

Flowers: are typically green with a purplish tinge but they may also be pink, purple or white. The plant stems end in a 10-30cm (4″ to 12″) raceme of stalked flowers each measuring approximately 13mm to 19mm (1/2″ to 3/4″) wide. There may be up to 50 flowers in a raceme but usually much less. Flowering time is July to August.

Broad-leaved Helleborine (Epipactis helleborine). A closeup of the flowers.

Roots: Helleborine form fleshy, fibrous roots and deep rhizomes, allowing multiple stems to arise from the same root stock. The roots require an association with mycorrhiza fungi in order for the plant to grow. According to the Royal Botanical Gardens, “rhizomes may go dormant and reappear after a three year absence.

Reproduction: Helleborine reproduce from seed (that require a period of cold before germinating) or vegetatively from the rhizomes. The small dust like seeds can spread far and wide on the wind, making this plant quite invasive. The seeds, like the roots, require an association with mycorrhiza fungi in order to germinate.

Distribution of Helleborine

Helleborine is native to Europe, but since it’s introduction to North America it now has a wide distribution across eastern Canada and the eastern United States as well as the western sea board.

It is showing up more and more in home gardens, lawns and path edges; where it tends to gravitate towards areas under tree canopies. You can also find it growing in ditches, swamps and riverbeds and in a variety of soil types. In a forest setting Epipactis helleborine can become highly invasive.

Management and Control of Broad-leaved Helleborine

Physical control: Dig the entire plant out being sure to get all of the rhizomous root system out. I assure you this is quite a task as the rhizomes can be very deep. Alternately you can keep cutting the plant down to the ground until you finally deplete the store house of starch in the rhizomes. Never let the plants go to seed.

Chemical control: for regions allowed the use of chemicals repeated spot sprays of Glyphosate will kill the plant and it’s rhizomes. Triclopyr (an organic systemic foliar herbicide and fungicide) is also an option, where permitted.

Photo credits: all photos by the author

References:

Broad-leaved helleborine: A weedy orchid invading lawns and flowerbeds – Gardening in Michigan (msu.edu)

Helleborine, Epipactis helleborine (L.) Crantz (friendsofthewildflowergarden.org)

Helleborine (Epipactis helleborine) – Ontario Wildflowers

Canadian Native Orchids – Epipactis helleborine (osrbg.ca)

Epipactis helleborine (Broad Leaved Helleborine): Go Orchids (northamericanorchidcenter.org)

Northern Ontario Plant Database (northernontarioflora.ca)

The Orchid Nobody Wants – Laidback Gardener

https://bsapubs.onlinelibrary.wiley.com/doi/full/10.3732/ajb.1100503#:~:text=Epipactis%20atrorubens%20and%20E.%20helleborine%20exhibited%20the%20largest,produced%20the%20longest%20seedling%20over%201%20cm%20long.

https://www.researchgate.net/figure/Developmental-stages-of-Epipactis-helleborine-seedlings-stage-1-ungerminated-seed_fig3_225296311

https://orchids.fandom.com/wiki/Epipactis_helleborine

Penn State Extension, 2018. Be on the Lookout for Invasive Orchids. Retrieved on Nov> 20, 2021 from: https://extension.psu.edu/be-on-the-lookout-for-invasive-orchids

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