The Botany of Common Milkweed

There is a patch in my garden that is designated especially for milkweed. I began doing this to feed the butterflies. The first year I did this I was stunned at the delightfully fragrance spewing from the flowers. Once I noticed those beautiful little flowers, they quickly became one of my very favorites! Common milkweed is pretty easy to find and ID, however there are many varieties of milkweed and a pretty bitter look-a-like. In this article I’ll delve into both, and teach you how to ID common milkweed.

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When learning to ID new plants, consult about 3 different sources to confirm the identity of the plant. Keep a wild plant field guide on hand. And make sure all sources are reputable.

Plant Family

Common milkweed, Asclepias syriaca, is in the milkweed subfamily of the Dogbane family, Asclepiadoideae.

Location

You’ll find common milkweed growing in fields, roadsides, and meadows. Typically this weed likes conditions on the moist side. They can be found standing alone or in patches. Often times if you see one there will be others close by. It is wild plant that is quite easy to find in Eastern North America. The shoots first appear in April/May. By late spring to early summer the flowers begin to emerge releasing their elegant aroma. By the end of summer the seed pods start to form.

Description

Milkweed is a perennial that can grow between 2-6 feet tall. They have been described to resemble broccoli (the flowerheads) or asparagus stalks but, I don’t really see or agree with that.

Stem/Stalk

Milkweed stems are hollow and contain a white milky sap that run throughout the plant. The sap is a bit sticky and can cause skin irritation. The stem is about 1/2 inch thick.

Leaves

The leaves are a rich shade of green that are smooth, ovate and grow opposite. Sometimes they can grow a lime green color too.

Flowers

The flowers grow in umbels on the upper portion of the plant. When the flowers open you’ll notice 5 white coronas sitting on top. Each corona has a tube like vessel called a hood and a little stalk, called a beak, sitting inside. The purplish color petals unfold under the corona in a star shape. There are 5 petals and 5 sepals.

Seeds

The milkweed seed pod are green when immature. Immature seeds inside the pod are white. As they age, the pods and seeds dry out turning brown and the white down fibers form. There are about 50 seeds per pod. That’s a guess. I’m going to count them out this year! When the pods dry they crack at a seam and the wind carries away the seeds away.

Look -a-Like

Common Dogbane can be mistaken for common milkweed, especially when young. I have no pictures of dogbane to offer at this time. However, in Samuel Thayer’s book, The Forager’s Harvest, he includes some pictures with particular attention to the stalk, and he gives a side by side written comparison between common milkweed and common dogbane. The biggest visible difference between the two is common milkweed is pubescent, meaning it contains hairs, on the young sprouts, while dogbane is completely smooth and hairless.

For a more detailed comparison of the two plants check out The Forager’s Harvest.

Other Milkweed Varieties

There are many milkweeds varieties found throughout North America. They are NOT all edible. In fact, some are poisonous.

Pictured below are Asclepias tuberosa, butterfly weed (orange flowers) and Asclepias incarnata, swamp weed (pink flowers). Both of these milkweed varieties have lance shaped leaves. They can be found through out most of North America. Butterfly weed grows in dry pinelands, meadows, prairies, and sandy fields. Swamp milkweed, on the other hand prefers wet climates. It grows in marshes, swamps, and wet meadows.

Keep an eye out for a post on wildcrafting common milkweed. Follow this blog or connect on Facebook to get updates and journal entries about foraging and feasting common milkweed. Until then, here are some articles you may find interesting.

Resources

“Wildflowers: Guides to Recognizing Just About Everything In Nature”, Reader’s Digest, North American Wildlife. page 214-217.
Elpel, Thomas. “Botany In a Day: The Patterns Method of Plant Identification” HOPS Press, LLC 1996, 2018. page 141.
Thayer, Samuel. “The Forager’s Harvest: A Guide to Identifying, Harvesting, and Preparing Edible Wild Plants” Forager’s Harvest Press. 2006. page 290-305

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The Botany of Common Milkweed

Plant Family

Location