White Milkweed

I had the urge to see nature beyond my backyard. So Buffy and I went to walk the gravel road leading up to Stone Face. An orchid used to grow there, and I thought I might find it in bloom. No orchids, but I did find this white milkweed.

 I  measured the flower used in the next 3 pictures: flower was 3/8 inch tall, petal width 1/2 inch, crown height and width both 3/16 of an inch.

Milkweeds have interesting and complicated flowers.

This angle shows the 5 petals (corollas) in the back, the 5 hoods (coronas) and the 5 incurved horns.

The pollen is in tiny saddle bags, which I think are the lighter pale pink parts in an upside-down V over the whitish part between. The parts are so tiny that I wasn’t able to remove the pollinia to photograph it. When an insect walks over the flower, it’s leg  slips between two of the hoods. Then when the insect jerks its leg out, it snags on the saddle bag, which then wraps around the insect’s leg. The pollinia dislodges from the leg when the insect visits the next flower, and pollination takes place.

White milkweed (Asclepias variegata) grows in open woods, thickets and usually in sandy or rocky soil. Its range covers roughly the eastern half of the U.S. The plants grow to 3 feet tall and have opposite leaves.

All milkweeds have a milky sap that can be toxic. Monarch butterflies only lay their eggs on milkweeds. The milky sap in the leaves makes the caterpillars toxic to predators.

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5 responses to this post.

  1. Posted by Therese on June 3, 2012 at 7:49 am

    Wonderful post! Is this milkweed like the orange flower I see? What an educational piece of work. Love your pictures…besides being stunning, they are so interesting and educational!

    Reply

  2. A gorgeous plant … I love learning about the incredible pollination mechanisms of flowers.

    Reply

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