Common Name(s):

antelope-horns milkweed

spider milkweed

spider antelope-horns

green-flowered milkweed

 

Scientific Name:

Asclepias asperula

 

Native Range:

AZ, CA, CO, ID, KS, NE, NM, NV, OK, TX, UT

​

USDA Symbol:

ASAS

 

Habitat:

• deserts

• sandy and rocky hillsides

 

Growing Conditions:

• Full sun

 

Plant Height:
• 1-3 feet (30-90 centimeters) tall

 

Stem Description:

• clump-forming

• upright and sprawling

• densely covered in tiny hairs

 

Leaf Description:

• 4-8 inches (10-20 centimeters) long

• 1-3 inches (2.5-7.5 centimeters) wide

• long, thick and linear

• leaf margins fold upward from the central vein in a distinctive “v” shape

• attachment to stem may be sessile or have a short petiole

 

Leaf Arrangement:

• whorled or alternate

 

Leaf Margin:

• entire

​

Flowering Period:

• April through July

​

Flower Description: 

• yellow and green

• corollas do not reflex backwards, but surround the hoods

• corollas are light green and hoods are white with maroon at the base

• clusters of flowers are 3-4 inches (7.5-10 centimeters) across

• approximately 20 flowers per umbel

• a single terminal umbel is produced per stem

​

Pod Description:

• 2-4 inches (5-10 centimeters) long

• slightly curved

• red, green or purple and rough

• sometimes have a striped pattern

• several pods may develop per stem if pollination has been successful

• look like "antelope horns"

​

Other Information:

• special value to native bees

• attracts predatory or parasitoid insects that prey upon pest insects