Indian Hemp is a bushy herbaceous perennial of the dogbane family (Apocynaceae) native to the Northeastern United States and Canada. All parts of this plant exude a milky juice when bruised and all plant parts are considered highly toxic to humans. and mammals. This plant typically grows in the wild in dry rocky or open woods, glades and prairies, as well as disturbed areas. Genus name comes from the classical Greek name for this or a related plant. Believed to be poisonous to dogs. Specific epithet means like Cannabis or hemp. Indian hemp grows 2 to 4 feet tall and 1 to 2 feet wide and prefers sandy well-drained soil in full sun. It will spread aggressively by rhizomes. Propagate by seed and division. The flowers appear late spring to late summer in clusters of small greenish-white flowers that attract many different pollinators. They are followed by seed pods that contain many silk tufted seeds. Native bees nest in the dead, hollow stems, so gardeners are encouraged to cut back dead stems to 12 to 24 inches and allow them to remain standing until they disintegrate on their own. Read more about best practices for stem-nesting bees in this NC Extension publication It can grow aggressively and is good for erosion control on slopes and stream banks. It is not recommended for garden use due to its aggressive behavior. Use in naturalized areas where they can spread freely. Insects, Diseases, or Other Plant Problems: No significant problems.
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.
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
Clay; Loam (Silt); Sand; Shallow Rocky
Soil drainage
Moist | Occasionally Dry
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 5 ft. 0 in. | Width: 1 ft. 6 in. - 2 ft. 6 in.
Growth rate
Rapid
Maintenance
High
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Texture
Coarse
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Elliptical; Ovate
Leaf margin
Entire
Hairs present
Yes
Leaf detail
The leaves are opposite with a smooth margin. The lower leaves will have a short stem, while the upper leaves are sessile. The leaves are 1 to 3-inches wide and half as much across. They are ovate to elliptical. The undersides have hairs. Yellow color in fall.
Fall color
Gold/Yellow
Flower color
Green; Pink; White
Flower form
Cyme
Flower shape
Urn
Flower detail
1-3 inch wide terminal panicles of greenish-white tubular or bell-shaped flowers. Individual flowers 1/4 inch. Additional clusters occur in the upper leaf axils. Flower blooms from May to July.
Bloom time
Spring; Summer
Fruit type
Capsule
Fruit size
> 3 inches long
Fruit detail
The fruit is a pair of hanging, slender, slightly curved pods 4 to 8 inches long with small brown seeds with a tuft of white hair to carry them in the wind.
Stem color
Red/Burgundy
Stem detail
The stem is smooth and red with a milky sap inside. It has ascending branches near the top of the stem.
Wildlife & Ecology
Native status
Native
Origin
All of North America
Distribution
All 48 states plus much of Canada
Wildlife value
Its flowers provides nectar to bees, butterflies and other pollinators. Dead stems are used by stem-nesting bees
Used by Native Americans and in herbal medicine to treat a variety of ailments. Fibers were used as thread for sewing or to make string, netting and other items.
Landscape Use
Landscape location
Naturalized Area
Landscape theme
Native Garden; Pollinator Garden
Garden tags
#drought tolerant #fire low flammability #poisonous #naturalizes #pollinator plant #native garden #NC native #native wildflower #dry soils tolerant #butterfly friendly #problem for dogs #problem for horses #problem for cats #nectar plant early summer #nectar plant late spring #nectar plant mid-summer #bee friendly #perennial #wildlife friendly #herb garden #NC Native Pollinator Plant #aggressive #wildflower #weedy #fiber plant #nesting site #beneficial insects #bat friendly #moth friendly
Problems & Resistance
Problems
Poisonous to Humans; Problem for Cats; Problem for Children; Problem for Dogs; Problem for Horses; Weedy
Resistant to
Fire
Propagation
Division; Seed
Fire risk
low flammability
Poison severity
High
Poison parts
Flowers; Fruits; Leaves; Roots; Seeds; Stems
Poison symptoms
Cardiac Arrest, nausea, vomiting, weakness, diarrhea. The milky sap from stems can cause blisters on skin.