Green Antelopehorn Milkweed
Asclepias viridis
ID_greenAntelopehorns_MW.jpg

Photo Citations

Naturedigger would like to thank the following individuals for their contributions to the Green antelopehorns milkweed (Asclepias viridis) identification slide:

 

Main flower image provided by: bHarding81; iNaturalist observation (cropped), CC BY-NC 4.0

Inset flower image provided by: Fiddleman; iNaturalist observation (cropped), CC BY-NC 4.0

Leaves and stems image by: Pynklyns; iNaturalist observation (cropped), Public domain

Inset leaf image provided by:  Jessica Bickell; iNaturalist observation (cropped)

Pod Image by: teChang; iNaturalist observation (cropped), CC BY-NC 4.0

Asclepias viridis Profile

Common Name(s):

green antelopehorn milkweed

green antelope-horn milkweed

spider milkweed

green milkweed

green-flowered milkweed

tall green milkweed

 

Scientific Name:

Asclepias viridis

 

Native Range:

AL, AR, FL, GA, IL, IN, KS, KY,

LA, MO, MS, NE, NM, OH, OK, SC,

TN, TX, WV

 

USDA Symbol:

ASVI2

Habitat: 

• dry areas

• overgrazed pastures

• prairies

• disturbed areas

• glades

• sandy or rocky soils

• dunes

 

Growing Conditions:

• full sun

• limestone soils

 

Plant Height: 1-3 feet (0.25-1 meter) tall

 

Stem Description:

• multiple stems unbranched

• larger plants may have up to ten stems

• thick

 

Leaf Description: 

• ovate to lanceolate - highly variable shape

• short petioles

• 2-4.75 inches (5-12 centimeters) long and 0.5-2.25 inches (1-5.5 centimeters) wide

• midvein may have pink or purplish tint

 

Leaf Arrangement:

• alternate to sub-opposite

 

Leaf Margin:

• entire, but often undulate

 

Leaf Surface:

• usually hairless but may have fine sparse hairs

• coarse

 

Flowering Period: 

• April through September

 

Flower Description:

• flowers grow in a tight umbel

• usually one umbel per plant

• ten plus flowers per umbel

• lack visible horns

• corolla (petals) are not reflexed backward

 

Flower Color:

• hoods are purple tinged with white

• hoods are below the stigmatic disc and rounded at the top

• corolla (petals) may be green or cream

• purple tinge in the center

 

Pod Description:

• usually erect

• thicker in the middle

• 2.5 inches (6-13 centimeters) long

• slightly hairy

• rough surface, not smooth

• form several pods per stem

• vertical stripes, may appear brown to burgundy

 

Other Information:

• endangered in Indiana and West Virginia

• prefers little vegetative competition

• similar species: antelope horns (A. asperula) and common milkweed (A. syriaca)

• one of the common names, spider milkweed, comes from the white spider

that lives on the plant