Slender Willow-herb Epilobium ciliatum
Other Common Name(s):
- Phonetic Spelling
- ep-ih-LOW-bee-um sil-ee-ATE-um
- Description
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Willowherbs are in the Onagraceae family. They are annuals that are more common in cool regions but occur occasionally as a cool-season weed in warmer areas. Seedlings are small and slow to establish, but once established, plants elongate to 18 inches tall. This weed is becoming more prevalent in container nurseries, likely spreading in contaminated nursery crops. Inspect liners to prevent introduction. Its seeds are spread by the wind. Preventing the plants from going to seed can curb its spread. Willowherbs are not well managed by herbicides currently labeled for use. Herbicide efficacy rankings for this species are based on limited experimental data. This weed is similar to northern willowherb (Epilobium hirsutum)
They can be found growing in locations where the soil has been disturbed such as in forests, along hillside ledges and ridges, in meadows and fields and along the shores of waterways.
The Scientific name ciliatum comes from the Greek word epi which translates to 'on the pod or capsule' and ciliatum referring to the hairs giving a fringe to the plant.
An easy plant to get children to draw and to get them involved in seeing the beauty of the great outdoors.
It is a host plant for the larvae of both moths and caterpillars. The moths include the Hawk moth (Sphingidae) and the Elephant hawk moth (Deilephila elpenor) while the butterflies include Mourning cloak (Nymphalis antiopa) and White admiral (Limenitis arthemis).
Insects, Diseases, and Other Plant Problems: No serious issues. Weedy plant that can be invasive. Non-invasive in North Carolina.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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Attributes:
- Genus:
- Epilobium
- Species:
- ciliatum
- Family:
- Onagraceae
- Life Cycle:
- Annual
- Perennial
- Recommended Propagation Strategy:
- Seed
- Country Or Region Of Origin:
- Asia, North and South America
- Distribution:
- AK, AZ, CA, CO, CT, DE. HI, IA, ID, IL, IN, KS, KY, MA, MD, ME, MI, MN, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY
- Wildlife Value:
- It serves as a host plant for several types of butterflies and moths. The flowers also attract hummingbirds.
- Play Value:
- Attracts Pollinators
- Wildlife Larval Host
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Whole Plant Traits:
- Plant Type:
- Annual
- Herbaceous Perennial
- Native Plant
- Weed
- Habit/Form:
- Clumping
- Erect
- Growth Rate:
- Rapid
- Maintenance:
- Medium
- Texture:
- Medium
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Loam (Silt)
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Occasional Flooding
- Occasionally Wet
- Available Space To Plant:
- 3 feet-6 feet
- NC Region:
- Coastal
- USDA Plant Hardiness Zone:
- 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
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Fruit:
- Fruit Color:
- Brown/Copper
- Fruit Type:
- Capsule
- Fruit Length:
- > 3 inches
- Fruit Description:
- The fruits are long, slim, hairy, four chambered capsules. They will split open when dry, disbursing seeds with a tuft of white hairs on their tips.
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Flowers:
- Flower Color:
- Blue
- Pink
- Purple/Lavender
- White
- Flower Inflorescence:
- Raceme
- Flower Bloom Time:
- Fall
- Summer
- Flower Shape:
- Star
- Flower Petals:
- 4-5 petals/rays
- Flower Size:
- < 1 inch
- Flower Description:
- The single, flowers can be pink/red, blue/purple, or white. They are single flowers with notched petals arising from the leaf axils on the upper portion of the plant. Each has four petals, sepals or tepals. The tepals or sepals are not fused, but separate.
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Leaves:
- Leaf Color:
- Green
- Leaf Feel:
- Glossy
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Opposite
- Leaf Shape:
- Elliptical
- Lanceolate
- Leaf Margin:
- Lobed
- Serrate
- Hairs Present:
- Yes
- Leaf Length:
- 1-3 inches
- Leaf Width:
- < 1 inch
- Leaf Description:
- The leaves are opposite on most of the plant. The upper stem can have alternate leaves. The leaves lack petioles are deeply veined and can have purple shading along the margins. The lower leaves are hairless while the leaves closer to the flowers have a small quantity of hairs.
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Stem:
- Stem Is Aromatic:
- No
- Stem Cross Section:
- Round
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Typically single stemmed, the upper portion has hairs, while the lower portion is hairless.
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Landscape:
- Landscape Location:
- Naturalized Area
- Pond
- Woodland
- Landscape Theme:
- Butterfly Garden
- Cottage Garden
- Native Garden
- Pollinator Garden
- Rain Garden
- Water Garden
- Attracts:
- Butterflies
- Hummingbirds
- Pollinators
- Songbirds
- Problems:
- Weedy
