I will admit that it took me a bit to figure this plant out. At first I thought I was looking at a significant bindweed infestation. These heart shaped leaves were twinging all over our fence. Then it flowered and I realized that this was no bindweed. This mysterious vine was none other than bluevine (also commonly called honeyvine, Cynanchum laeve)
Believe it or not, this is a species of milkweed. Though not in the genus Asclepias, it nonetheless belongs within the same family (Apocynaceae) and is close enough in relation to function as a host for species such as the charismatic monarch butterfly.
Mention this in many of the native plant groups and you are bound to be met with resistance. Because this species can be weedy, many people seem to want to overlook its value as a food source for monarch caterpillars. There is even scientific evidence to suggest that there are no significant differences in fitness and survival among caterpillars raised on either common milkweed or bluevine. The authors of one study even make the conclusion that,
“Given the abundance of honeyvine milkweed in the east-central United States, this species may be a more important host plant for the monarch than has been generally recognized.”
The biggest problem people seem to have with bluevine is that it can be very aggressive in disturbed soils. In many places it is considered a serious agricultural pest. Like its milkweed cousins, its seeds erupt from pods and are born on light, feathery filaments. Because of this they can travel great distances on the slightest breeze. They germinate readily and, once established, the plant can regrow from rootstock.
Regardless of where you stand on bluevine, there is no denying that it is an interesting species. Its flowers are packed into clusters and smell heavily of honey. They are primarily visited by small solitary bees. As is typical of the family, bluevine produces some serious chemical defenses. As such, it is generally ignored by mammalian herbivores but is readily consumed by many of the other native milkweed specialists in North America. So, I urge you to consider giving bluevine a chance. You may grow to love its hardy disposition and its great ecological value.