Feathery Seeds
On a lovely early-February afternoon, I received a text from both Sunshine and Lisa concerning some seed pods on a vine they’d discovered while on a walk. The seeds from the pods floated out on white, fuzzy and even fluffy structures. That “fluff” is extraordinarily effective at allowing the seeds to disperse on the wind, and the technical term for it is “coma”. So effective is this coma that, when the winds and humidity are right, milkweed seeds are capable of dispersing several miles from the plant from which they originate.
In our visits, we never just leave it at that, now do we?! Of course not! We must look at what plant those seeds and seed pods belong to. We must look into where that plant fits into the landscape and what connections it has to other species found on Harmony Hill.
Those seeds, floating ever so gracefully on the wind, belong to a plant with gracious plenty common names! Referred to as Honeyvine, Milkweed Vine, Blue Vine and Climbing Milkweed among other names, it has just one scientific name: (Cynanchum laeve).
Found from New York to Florida along the east coast, its range stretches as far west as Nebraska and down to Texas. Some populations are found in limited areas of Idaho, but it’s believed by some that those populations were introduced. The scientific name means “smooth (or light) dog choker”. WHAT?!?!? What does a vine in the milkweed family have to do with choking a dog? Well, this vine can tightly wind around everything from trees and fenceposts to utility piles and wire. In fact, it can wrap so well, it could hypothetically “choke a dog”.
Belonging to the Asclepiadaceae Family, this vine brings us back to a name we discussed a couple of weeks ago when we visited the snakes of Harmony Hill. If you’ll recall, we discussed Asclepius, snakes and how they relate to the American Medical Association symbol. Well, here we are, connecting milkweeds to snakes with our old friend, Asclepius. Milkweeds have long been used for myriad medicinal uses, being used directly or added to tinctures to treat pleurisy, coughs, blood ailments, rashes, sore throat and even to stimulate milk production in mothers. (The efficacy of some of these treatments can be debated.) With such a wide medicinal use, is it any wonder this plant has been linked to our friend, Asclepius the healer?
Like other members of the family, this vine is used as a larval food source for the caterpillars of Monarch Butterflies (Danaus plexippus). And, as a member of the milkweed family, it has become an important component on the landscape to help out the falling populations of this incredible butterfly. Milkweed Vine doesn’t have the prominent milky sap often found in its more traditional relatives. But that doesn’t make it any less sappy. In fact, recent studies have shown Milkweed Vine to be used by Monarch caterpillars more often than previously thought. It is also a larval food source for the caterpillars of the Milkweed Tussock Moth (Euchaetes egle). However, the caterpillars of the Monarch Butterfly prefer fresh, new growth on milkweed plants. Meanwhile, the caterpillars of the Milkweed Tussock Moth prefer to munch on older growth of milkweed plants. This difference in preferences of food means the two species don’t compete against one another!
(We will encounter Tussock Moth caterpillars as the spring and summer progress, so I will save a longer look into the story behind them for a future installment. However, I will say this in our current conversation… Don’t touch Tussock Moth caterpillars! They can sting you with their stinging hairs! Take a look at the fuzzy caterpillar in the image below to see what to avoid.)
Unless this plant is growing in an area near livestock, I always recommend leaving to grow and thrive.
About that… in large doses, this plant can be toxic to cattle, horses and humans. With that in mind, I ask that you be mindful to keep it from growing near the horses at Harmony Hill. Now, it would have to grow densely, and the horses would have to eat a good bit of this plant for it to have an adverse effect. But I think it’s always best to keep potential harm away as a precaution. Also, this vine can sprout from portions of roots left in the ground after pulling, making it difficult to remove from an area without chemicals.
The toxin in the plant that makes it harmful is the PRECISE REASON Monarch caterpillars and Milkweed Tussock Moth caterpillars use milkweeds as their larval food source. They are able to process and store the toxin, primarily a type of cardiac glycoside, to make predators sick. (And, if enough is ingested, die.) It’s a terrific deterrent to predation and both the butterfly and the moth advertise this danger in their bright colors.
In the spring, this perennial vine will sprout and begin growing up any structure it is near. As all vines do, it will climb in search of life-giving sunshine, as it develops its dark green leaves that are a blend of heart and triangular in shape. The stem will be mostly green, but often has a slight reddish hue. While it can be mostly smooth in texture, it may also have a slight pubescence, these small hairs can often be overlooked, but are tiny and white when present. The flowers will develop fairly quickly in the spring and they look quite similar to the flowers found on other milkweeds. Not long after pollination, the seed pods will begin developing. This is usually in the early part of the summer in South Carolina.
After the seeds mature, the pods will begin drying out and will open. Upon opening, the process of seeding will again start on Harmony Hill, with the seeds taking to the air and riding the winds to find a new place to plant themselves. They are able to germinate in almost any soil type and can do well in almost any moisture level. The seeds begin sprouting quite early in the year, when the temperatures begin warming and the sun shines a little longer; which, in South Carolina could be mid-February.
There are a couple of vines that resemble Milkweed Vine, with one vine, Black Swallowwort (Vincetoxicum nigrum) being an introduced species. But, I hope that plant has not made its way to Harmony Hill yet!