Grazing Oklahoma: Passionflower

(Photo courtesy of the Noble Research Institute)

By Mike Proctor

Characteristics: Passionflower is a large, herbaceous, perennial vine with tendrils and three-lobed leaves. Foliage tends to be a dark green.

The sepals and petals are white with some additional structures providing the purple coloration. These thread-like structures act as nectar guides and protect the nectar from non-pollinators and dilution by rain. The vines climb to some extent, but tend to sprawl across any other vegetation or support that is available.

Area of Importance: Passionflower occurs in the eastern half of Oklahoma and most of the southeastern United States, extending south into South America. It can be found in fence rows, creek bottoms or open areas.

Attributes: Native people throughout the range of this plant used passionflower for a variety of medicinal purposes as well as for food.

There is not much information available about the use of this plant by livestock. I rarely see it inside a fence with cattle, so I suspect they eat it when they get the chance. It is not likely to be abundant enough to consider it a useful forage.

There are more than 400 species in this genus, many of which are cultivated for fruit. Passionflower is an important food plant for the larvae of several butterfly species, especially fritillaries and longwings. Bobwhite quail and song birds eat the seed. The complexity of the flowers is a pretty good indication of a close relationship with their pollinators. Flower structure restricts access to the nectar to only certain pollinators. This is a strategy seen in plant species that are unable to self-pollinate.

This means a successful pollinator is likely to have been at the flower of another individual. Even the pollinators tend to specialize for passionflowers.

Read the July issue to learn more about Passionflower.