Classification Hierarchy
Kingdom Plantae
Subkingdom Tracheophyta
Superdivision Spermatophyta
Division Magnoliophyta
Class Magnoliopsida
Subclass Asteridae
Order Gentianales
Family Apocynaceae
Genus Asclepias
Species Asclepias engelmanniana
Engelmann's milkweed

Date: XXXXXXXX 2010. Location: XXXXXXXXX (map)

BONAP, FNA, ITIS, USDA, VPI

Scientific Name: Asclepias engelmanniana (Asclepias named for Asclepius; engelmanniana in honor of botanist Georg Engelmann)

Common Name: Engelmann's milkweed

Origin: Native

Notes: Endangered in Iowa—a few individuals have been identified in western Iowa but the plants main range is to the south and west of Iowa often in sandy and stoney soils.

Only 4 Iowa milkweeds have such slender leaves. A. stenophylla is most like A. engelmanniana since both are rated as Endangered in Iowa, both have larger distributions to the south and west of Iowa, and each species has been reported only a few times in western Iowa. The other 2 species are A. hirtella which has slightly broader leaves and though scarce, has been reported in northern counties in Iowa, and A. verticillata which is common in Iowa. It is shorter and its leaves are attached in whorls and are more numerous than either of the Endangered species.

Additional references: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12.

Field Marks for Identification:

Flowers: June; corolla light-green, corona yellow.

Leaves: long and slender, sessile on an unbranched erect stem up to 4 feet high.

Glossaries of botanical terms: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Engelmann's milkweed-1 Engelmann's milkweed-2 Engelmann's milkweed-3 Engelmann's milkweed-4