Asclepias exaltata Indiana Dunes

Family:     Apocynaceae (Dogbane family)

Duration:  Perennial

Height:     60-183 cm (2-6 ft)

Blooming: June-July.

 

Poke Milkweed

Asclepias exaltata L.

Stems: the stems are green with sometimes a purple hue. The stems attaching to the flowers are a pinkish purple. Adult plants usually produce 1-2 stems with around 3-4 umbels

Flowers: small, 5-parted flower that show a soft white with hints of purple and pink. They grow in a drooping or weeping cluster. This cluster is more sparse than the common milkweed (Asclepias syriaca).

Leaves: simple, glabrous (with no hair) on the upper surface. The lower surface of the leaf sometimes has really fine white hair on the veins. Leaves are attached to the stem by a petiole that is 2.5-7.5 cm (1-3 in) in length. Poke milkweed's leaves can be quite large growing up to 20 cm (8 in) long and 7.5 cm (3 in) wide. When broken, a milky latex sap oozes out. Leaf arrangement is opposite.

Fruits: are follicles maturing in September and October.  

Sun: part sun to shade

Ideal conditions: wet soil in full sun to partial shade

Asclepias exaltata at Indiana Dunes

Comments: 

Unlike most milkweeds that grow in Northwest Indiana, poke milkweed grows only through seed and not through vegetative means such as rhizomes. It can also spend many of its juvenile years without flowering. Poke milkweed can be distinguished by other milkweeds by the combination of these traits: (1) the leaves are petiolated, (2) pedicels 2.5-4.5 cm long at maturity (Michigan Flora), (3) plants hairless or minutely hairy.

 

Etymology: The genus Asclepias was named by Carl Linnaeus after the Greek god of medicine, Asclepius. The name, exaltata, comes from the Latin word, "exalted".  

Asclepias exaltata Indiana

all photos by Nathanael Pilla

Landscape:  Poke milkweed is a great plant to put in the more shaded areas of your garden. It attracts butterflies, moths, and bees among many other pollinators. Small herbivores do enjoy munching on the leaves so young plants may need a little help to began with.

Species Present and Native

Michigan Flora Online. Reznicek, A.A., E. G. Voss, and B. S. Walters. 2011. University of Michigan. Web. August 30, 2016. http://michiganflora.net/genus.aspx?id=Asclepias.

Peattie, D.C. (1930). Flora of the Indiana Dunes. Field Museum of Natural History, Chicago, IL. pp. 308.

 

Shannon, T. R. and R. Wyatt. 1986. Reproductive biology of Asclepias exaltata. American Journal of Botany: 11-20.