Green antelopehorn is an herbaceous perennial in the dogbane (Apocynaceae) family that is native to the central and east central United States. It is found in calcareous hammocks, dry woodlands, pine rocklands, and prairies. The Genus name honors Asclepius (Asklepios), the Greek god of medicine; the species name is Latin for “green,” referring to the flower color. Requires a sunny, well-drained spot and prefers soil with a neutral pH. Propagate from seed. Best in naturalized areas, meadow, prairie or drought-tolerant plantings; also consider green antelopehorn for butterfly, pollinator gardens, or in a border if there isn't too much competition from other plants. Milkweed is an important food source for the Monarch butterfly caterpillar ( Danaus plexippus ) . Insects, Diseases, and Other Plant Problems: No significant disease problems. Most common milkweed pests (aphids, milkweed beetles, Monarch larvae, and milkweed tussock moth larvae) are not problematic, but both large and small milkweed bugs can be very damaging to seed pods.
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)
Soil texture
High Organic Matter; Loam (Silt); Sand; Shallow Rocky
Soil pH
Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 1 ft. 6 in. - 2 ft. 6 in. | Width: 1 ft. 0 in. - 2 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (1-3 ft)
Form & Appearance
Habit / form
Erect
Texture
Medium
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Lanceolate; Ovate
Leaf margin
Entire
Leaf feel
Smooth
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
Leaves are simple, alternate to sub-opposite, with sessile to short petiolate attachment, ovate to lanceolate shaped, white veins, 2.5 to 6 inches long and 1 to 7 inches wide. The leaf's undersides are lighter than the dark green upper surfaces with minute hairs.
Flower color
Green; Purple/Lavender
Flower value
Fragrant; Showy
Flower form
Umbel
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
Terminal umbels 3 to 5 inches wide are comprised of 10 or more green flowers with 5 upright corolla lobes (petals), topped with purple hoods; horns absent. Bloom time is spring and summer.
Bloom time
Spring; Summer
Fruit color
Brown/Copper
Fruit type
Follicle
Fruit size
> 3 inches long, 1-3 inches wide
Fruit detail
Fruits are slightly hairy follicles forming upright 3- to 6-inch long 2.5-inch wide pods filled with 50 to 100 brown seeds with attached coma (white fluffy fiber) that facilitates wind dispersal.
Stem color
Green; Purple/Lavender
Stem detail
Multiple stems growing from the plant's base are green to purple, sometimes hairy toward the tips.
Wildlife & Ecology
Native status
Unknown
Origin
Midwest, South-central and southeastern USA
Distribution
AL, AR, FL, GA, IL, IN, KS, KY, LA, MO, MS, NE, OH, OK , SC, TN, TX, WV
Wildlife value
Nectar and larval host plant that attracts bees, butterflies (notably Monarchs), hummingbirds (milkweeds are a source of insects as well as nectar), moths (especially milkweed tussock moths and their larvae), pollinators, predatory Insects, and specialized bees.
#herbaceous perennial #showy flowers #pollinator garden #low maintenance #drought tolerant #naturalized area #butterfly caterpillar host #bee friendly #border #Monarch butterfly #butterfly friendly #problem for dogs #problem for horses #problem for cats
Problems & Resistance
Insect problems
Milkweed Bug
Problems
Poisonous to Humans; Problem for Cats; Problem for Dogs; Problem for Horses
Resistant to
Deer
Propagation
Seed
Poison severity
Low
Poison parts
Flowers; Leaves; Stems
Poison symptoms
Can cause stomach upset, nausea, vomiting, abdominal pain, diarrhea, weakness, lethargy, and confusion if eaten in quantity. Milky sap can cause contact dermatitis and eye irritation.