Common Name(s):

Engelmann's milkweed

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Scientific Name:

Asclepias engelmanniana

 

Native Range:

AZ, CO, IA, KS, NE, NM, OK, TX, UT, WY

 

USDA Symbol:

ASEN

 

Habitat:

• sandy, rocky or limestone soils

• creeks and canyons

• open pine forests and woodlands

• shortgrass prairies

 

Growing Conditions:

• dry, well-drained soil

• full sun

 

Plant Height:
• 1-5 feet (0.3-1.5 meters) tall

 

Stem Description:

• tall and thick

• multiple stems branching from the ground

• may be green, reddish or brownish

 

Leaf Description: 

• linear

• 2-10 inches (5-25 centimeters) long; 0.04-0.3 inch (1-8 millimeters) wide

• sparse

• closer together near the lower third

• sessile (no petiole), and does not clasp

• may be folded inward from mid vein

 

Leaf Arrangement:

• alternate becoming whorled as progress up the stem

 

Leaf Margin:

• entire

 

Leaf Surface:

• glabrous (hairless) to slightly hairy

 

Flowering Period:

• June through September

Flower Description:

• umbel on thick peduncles or sessile

• umbel is approximately 2 inches (5 centimeters ) wide

• flowers near upper portion of stem at leaf nodes

• hoods are broad, saclike and are positioned close to the central column

• horns attached near the middle of the hoods, but not visible

 

Flower Color:

• pale green to yellow

• tinges of purple on the underside of petals near the tips

 

Pod Description:

• erect on deflexed pedicels

• curved and conical

• up to 6 inches (2.4 centimeters) long with lengthwise wrinkles and a pointed tip

• greenish, but turns tan with age

• smooth or slightly hairy

 

Other Information:

• recognized by pollination ecologists as attracting large numbers of native bees (including honey and bumble bees)

• named for American botanist George Engelmann

• endangered in Iowa

 

 

 

To Locate and Purchase Seeds (when available):

 

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Xerces Society Milkweed Seed Finder 

 

Milkweed and Wildflower Vendors

 

Grow Milkweed Plants

 

 

For More Information About This Species Visit:

 

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Lady Bird Johnson Wildflower Center

 

Arizona Cooperative Extension

 

USDA Plants Database

 

Kansas Wildflowers and Grasses

 

SEINet Portal Network

 

iNaturalist