Summer Botany: Meet the Milkweeds

Strolling the neighborhood on a cool July morning, in search of any newly-blooming botanical delights (thanks to our all-too-brief bout of monsoonal rains), from a distance I recognized something different. From a distance it looked like a common pepper plant, or maybe a spectacle pod? Coming closer I thought, “shepherd’s purse” with those tiny satchel-like seeds!  Or could it be bedstraw, with such an intoxicating fragrance?  Finally facing this spindly, narrow-leafed plant, I reached down to a stem and prepared to take a sniff when I was surprised twice!

An ant that had been busy gathering nectar (?) had leaped into my hand and bit me, hard! Obviously he was extremely upset at being disturbed and wanted me to know about it. I instantly dropped the stem and when I flicked the ant from my now throbbing finger, noticed an army of busy ants climbing up and down this tasty plant.

It was then that my surprise was complete. The flowers were unmistakable and recognizable.  This plant was a member of the Dogbane family ….. a beautiful Milkweed! Now I had to learn which species of Asclepias this one was that had such tiny flowers?

This new-to-me milkweed turns out to be Horsetail Milkweed, Asclepias subverticillata (subverticillata means “almost whorled” and refers to the leaf arrangement). This pretty milkweed is a common plant found along roadside habitats throughout the desert southwest. Although the narrow-leaved stems of my plants were less than 18” tall, there are reports of plants growing to 40”.  Wow. As with all milkweed species, this one is a suitable host plant for Monarch caterpillars.  I wonder if the taller ones are more easily seen by the adults as they flit around looking for a place to lay eggs? Maybe I should water my small population?

My Horsetail Milkweed

While pondering thoughts about butterflies, caterpillars and other pollinators, I began studying the exotic flowers of this milkweed. Such a highly evolved flower, with not just a calyx of 5 sepals and corolla of 5 reflexed petals, but a crowning Corona consisting of weirdly fused stamens and pistils. So many beautifully strange parts. Surely these plants require extra savvy pollinators to help the milkweed go from flower to fruit (aka follicle ….. when mature release those lovely gossamer silk-tethered seeds on a windy day).

I hastily gathered a few more facts and observations about this Horsetail Milkweed, because my curiosity was rapidly taking me down one of my fascinating rabbit trails.  Time to Geek Out big time!  I couldn’t resist learning more about the fascinating milkweed flower structures and just what clever insects have figured out the secrets to their successful pollination. 

So much information!

So down the trail I ran, delving into the peculiarities of the complex flowers, “dissecting” all of their parts and mechanisms, and learning how they function in manipulating insects to carry those waxy masses of pollen from one plant to another. During this odyssey of discovery, I learned just how important this Asclepias genus is to the survival of Monarch butterflies … as the only host plants for their caterpillars, as an important nectar source for adults, and for their dependence on strong insect pollinators to fertilize the flowers and ensure future populations of milkweeds continue to grow across the butterfly’s range.

My ”Pony” page of more information …… accordion style!
Accordion foldout ….. Milkweed & Bee Relationship (Mutualism)
More details!

As with all of my rabbit trail adventures, this was educational, eye-opening and exceptionally fun.  The research that’s been conducted on the Asclepias genus seemed never ending (even though I couldn’t learn the purpose the corona’s horn serves).  It’s so important to understand how critical the connections are between different species for their survival, and how environmental impacts such as climate change and pesticide use can crumble an already teetering house of cards.

Accordion pullout ….. Monarch/Milkweed Relationship (Mutualism)
More details!

Your turn! Take a walk outside today and be amazed by something new!


  1. hdeishere says:

    Your work never ceases to amaze me. Thank you for sharing your talent, intelligence and love of nature.

    Liked by 1 person

    1. Thank you so very much for such a wonderful comment Helene!


  2. How wonderful to discover a lovely milkweed, so important to the Monarchs! I haven’t heard of this type of milkweed. I grew up in Ontario, Canada where Monarch butterflies were a staple, but I don’t get to see them here in Seattle eastside. Your pages are magnificent with detail and I’m going to take some time over the next few days to read your amazing accordion fold-outs as I want to learn about the bees and the Monarch/Milkweed relationship! I just started reading “Bicycling with Butterflies” about a woman who cycles along with the Monarch migration from their Mexico wintering site up to Canada and back again. I’m looking forward to following her journey!

    Liked by 1 person

    1. Thanks so much, Karen, for the super comments, and now for taking the time to read the details. I plan on observing my horsetail milkweed (with a magnifying glass) to see if this species is being pollinated by the ants or if they are only taking advantage of the rich supply of nectar. The book you’re reading sounds so interesting. I will have to find a copy! Really, you don’t have monarchs in your area? Now I’m wondering why!

      Liked by 1 person

      1. The monarchs are more east of the Cascade mtn. range. I think we get the odd one floating through Seattle, but not many!

        Liked by 1 person

  3. Thais Rosan says:

    Just discovered your blog and I love it! So inspiring, thank you for sharing your love of nature in such a beautiful way!


    1. Hi Thais Rosan! I’m so happy you’ve found my blog. Thanks so much for the lovely comments and support!

      Liked by 1 person

  4. sgoodman56 says:

    I need to plant some milkweed!!!

    Liked by 1 person

  5. Deidre Pistochini says:

    Fascinating and detailed post! Having been a biology major in college, I can appreciate your dissection of the plant parts and it’s relationship with the Monarch butterfly life cycle. Beautiful art, too. 😊

    Liked by 1 person

    1. Thanks so very much for your comments Deidre! So glad you can relate. There’s something intoxicating about details. I’m still chasing this milkweed and learning about its pollinators. Spent time observing bugs coming and going, pulled out my hand lens and found a lot of lost legs stuck in milkweed flowers, and today an army of bright orange aphids are lining up and down the stems like it’s a bar! Now I’m full of more questions! So much fun!


  6. I love your notebooks! Beautiful and informative!


    1. Thank you so much for the comments and all the “likes” on previous posts! I hope you continue to enjoy my nature journaling blog!


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