Monarchs and Milkweeds

 

The Restoration Manager at Pleasant Valley Conservancy, Amanda Budyak, is pictured at right.  She took most of the milkweed photos in this blog post.  Here, she is capturing turk’s cap lily in the marsh.

“This world of dew, is a world of dew, and yet, and yet… “  Kobayashi Issa

There is always more to be learned and said about milkweeds and monarchs and migrations.  About pollinators and poisons and the forever dance of plants and insects.  The two-step of the plant to attract just enough, yet also to repel.  The insect waltz to get the goodies, yet avoid, or live with, the lethal juices.  

Purple Milkweed (Asclepius purperascens).  This is the milkweed for which Pleasant Valley is known.  It grows in the savannas and is unpredictable from year to year as to whether it will bloom, form a seed pod, or even show up.  We rejoice when it does.  Poke Milkweed (A. exaltata) also grows in the savannas.

Milkweed pollination is accomplished mainly by bees and wasps.  That’s because the milkweed flowers literally saddle the insects with two giant pollen sacs at a time, and the pollinators need to be strong fliers to be able to take off again after this burden is attached against their will.

Butterfly Milkweed (A. tuberosa). Monarchs lay their eggs on milkweeds, and their larvae require milkweed leaves to develop. Over two dozen milkweed species serve this purpose in Wisconsin.  Ironically, Butterfly Milkweed isn’t their favorite for egg laying, but they do enjoy feeding on the nectar of the flowers.  If you want to plant milkweeds for monarchs, be sure to plant those native to your geographic area and plant several different species.  

Besides those pictured here, choose from whorled, prairie, clasping, sand, spider, short green, broadleaf, showy, and more.  Such as:

Swamp Milkweed (A. incarnata). This was the first milkweed scientific name I learned because I love it so, both the name and the plant.  The blossoms are beauty incarnate.  At this time of year they are islands of brightness as you trudge through the marshes, carefully.  All milkweeds develop pods that contain multiple rows of tightly packed flat, silky-winged seeds.  When the pods ripen, they split open, and the seeds are launched by the wind into the wind.  Pods familiar to most are seen below.

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Common Milkweed (A. syriaca). This is a favorite of monarchs, is easy to grow, and small amounts of seeds can be obtained for the asking from us or Madison Audubon (I’m making an assumption here).  All milkweeds and all of their leaves, flowers, roots shoots, seed pods, etc contain a milky sap that is toxic.  Do not eat these plants.  Wash your hands after handling the leaves and seed pods.

Monarchs are pretty famous these days, and this is just a brief reminder of their life cycle.  I wonder how their larvae are able to eat so much lethal milkweed toxin and not die.  The adults retain enough of this cardiac glycoside to repel predation, by birds for example.  Do we have any theories about how such a tolerance could have evolved?  We sometimes see orange and black milkweed bugs swarming over the pods.  They must be able to eat this poison too?  What would happen if we did eat milkweed leaves?  Native Americans used milkweed as medicine.  How did that work?  All questions for my next blog, where I will also feature young scientists giving monarchs a helping hand.