Students for Stewardship The Cork Board
← Back to the library

Japanese cobra lily

Arisaema sikokianum (air-uh-SEE-muh see-ko-kee-AY-num)

Family: Araceae Non-native Herbaceous (1-3 ft)

Japanese Jack-in-the-pulpit is an herbaceous flowering plant in the aroid family (Araceae) native to the island of Shikoku in Japan and found in shady, moist woodland sites. The species epithet is Latin for "of Shikoku." This plant grows 1.5 to 2 feet tall and wide in hummus-rich, moist, well-drained soils in partial to full shade. It is best grown from corms, as plants grown from seed can take 3 to 5 years to bloom. Plant corms 3 to 4 inches deep and leave them undisturbed once established. The inflorescence is comprised of a spathe, which is a sheathing bract that is dark purple on the outside and white on the inside, and a spadix, which is an unbranched spike of tiny flowers. The spadix is swollen and white, surrounded by the spathe. Blooming occurs in spring. It is the showiest of the plants in the group. The flower may be followed by a cone of red berries in summer. Use Japanese Jack-in-the-pulpit in a woodland garden, in shade to partial shade, along with other shade-loving plants, as it will go dormant in mid- to late-summer. Use in a cottage or Asian garden theme or in a container. Some people may experience a mild dermatitis when handling the plant. Insects, Diseases, and Other Plant Problems: No significant problems. Watch for slugs and vine weevils. More information on Arisaema .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 50 attributes.

How it fits the guild

Guild layer 4 - Herbaceous (1-3 ft)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Native alternatives Arisaema triphyllum

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial
Life cycle
Perennial
USDA zones
5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a
Light
Deep shade (Less than 2 hours to no direct sunlight) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter
Soil drainage
Good Drainage | Moist
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 1 ft. 6 in. - 2 ft. 0 in. | Width: 1 ft. 6 in. - 2 ft. 0 in.
Growth rate
Medium
Maintenance
Medium
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Erect
Texture
Medium
Leaf color
Green; Red/Burgundy
Leaf margin
Lobed
Hairs present
No
Leaf detail
The stem arising from the corms produces a pair of 5-lobed leaves, some of which may have red markings
Flower color
Purple/Lavender; White
Flower shape
Tubular
Flower size
> 6 inches
Flower detail
The inflorescence is a spadix up to 8 inches long ans swollen at the apex. It is surrounded by the spathe that is dark purple on the outside and pure white on the inside and a large striped hood of purple, green and white. Bloom time is spring
Bloom time
Spring
Fruit color
Red/Burgundy
Fruit type
Berry
Fruit value
Showy
Fruit detail
The spathe may produce a dense cone of red berries in summer to fall
Stem color
Green
Stem detail
A single fleshy stem arises from the corm
Wildlife & Ecology
Native status
Non-native
Origin
Japan
Food & Medicine
Harvest time
Fall; Summer
Fruit type
Berry
Landscape Use
Landscape location
Container; Woodland
Landscape theme
Asian Garden; Cottage Garden; Shade Garden
Design feature
Border; Small groups
Garden tags
#partial shade tolerant #herbaceous perennial #showy flowers #woodland garden #shade tolerant #spadix #spring flowers #purple flowers #cottage garden #container plant
Problems & Resistance
Problems
Poisonous to Humans; Problem for Cats; Problem for Children; Problem for Dogs; Problem for Horses
Resistant to
Deer
Poison severity
Low
Poison parts
Fruits; Leaves; Roots; Sap/Juice
Poison symptoms
Irritation and swelling of the lips, tongue, and throat if it is eaten raw. Handling the fruit pulp or leaf sap may cause mild dermatitis.
Toxic principle
calcium oxalate
Contact dermatitis
Yes
Toxicity summary
Low severity poison; parts: Fruits; Leaves; Roots; Sap/Juice; contact dermatitis

Planted at Hunnicutt

Nobody’s planted this one yet.