Yellow passion vine is a perennial vine that climbs by means of tendrils and has stems that can reach 3–5 meters (10–16 feet) in length. It favors shady, moist woodlands and forests but is remarkably adaptable so long as it is not subjected to long spells of hot and dry conditions. The leaves can vary from solid, dark green to pale green, often with beautiful, silvery variegations on the upper surface, as seen in the image above of a plant obtained from Meadow Beauty Nursery. The tiny flowers are only about 1.5 centimeters (half an inch) in diameter and are nondescript from a distance; however, they reward close examination due to their intricate and delicate structure.
As with other native passion vines, yellow passion vine may be profitably grown in butterfly gardens, where its leaves are used as a caterpillar food plant by gulf fritillaries (Agraulis vanillae), julias (Dryas julia), and zebra longwings (Heliconius charitonius). This interesting native vine also has a remarkable association with a highly specialized bee, the passiflora bee, Anthemurgus passiflorae. It is a small black bee whose females collect, as the sole food source for their larvae, only the pollen of yellow passion vines (Neff 2003).
I once attended a lecture by a butterfly gardener who stated that "we should grow pretty passion vines since they are all equal as far as the butterflies are concerned." By this, she meant that we should grow large-flowered passion vines and ignore the small-flowered native passion vines. But she was wrong on two counts. First, some non-native passion vines are lethal to the caterpillars that normally feed on native passion vines, so it would make a difference to the butterflies whether or not a passion vine is native. And it would make a big difference to specialist insects such as the passiflora bee, whose progeny would starve without the native yellow passion vine.
Yellow passion vine is botanically interesting as the most cold-hardy and northern growing of any passion vine native to the Western Hemisphere. It occurs as a native plant only in the United States, where it has a considerable range that includes much of the eastern half of our country.
Map courtesy of the United States Department of Agriculture Plants Database.
- Neff, J.L. 2003. The passionflower bee: Anthemurgus passiflorae. Passiflora 13(1): 7–9. Internet
© 2010 Rufino Osorio (exclusive of the USDA map).