Scientific Family
Asclepiadaceae
Other common names
antelope horns
antelopehorn milkweed
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Perennial
Height
1 to 2 feet
Riparian
No
A clump-forming plant with an upright or sprawling habit. The stems are densely covered with minute hairs. Milkweeds are the primary food source for Monarch caterpillars.
Several stemmed perennial; woody rhizome; leaves alternate, narrow, tapering, ascending; flowers in large head-like clusters, individual flowers bowl-shaped, 5 greenish-white petals with horn-like purplish appendages (hoods), petals erect in full flower.
Habitat
Dry plains, slopes, and clearings in oak woodlands and pine forests.
Plant Community
Pinyon Juniper Woodlands
Montane Conifer Forest
Grasslands
Low elevation
3000
High elevation
9000
Flower Characteristics
Rounded 3 to 4 inches wide clusters of fragrant greenish-white flowers that are to 1/2 inch wide, 5-parted and include sepals, petals, a (corona) arising from the middle of the petals, upright hoods that look like petals and purplish horns.
Flower color
Greenish-white
Flower shape
Regular
Tubular
No
First bloom month
April
Last bloom month
August
Flower clusters
Rounded
Leaf and Stem Characteristics
Narrow, 4 to 8 inches long with a grayish mid-vein, pointed tips and wavy edges that curl upward. The long, thick, narrow leaves are often folded lengthwise.
Leaf type
Simple
Leaf color
Dark green
Leaf shape
Narrow
Leaf margin
Smooth
Leaves clasp
No
Leaf hairs
Stems
Spines
No
Fruit and Seed Characteristics
Stout, 6 inches long, green pod with olive-green and pink streaks. Pod has lengthwise wrinkles and a pointed tip. As they grow and begin to curve, they resemble antelope horns.
Fruit type
Pod
Fruit color
Green
Pod contains flat brown seeds.