Passionflower in the Arboretum

Every year, Hummingbird Central puts out a map where users can report their first sightings of migratory hummingbirds. Let's play a similar game. Have you seen any Gulf fritillaries (Agraulis vanillae) yet? At the arboretum, we're still waiting on them. This year, the arboretum has two species of passionflower for the caterpillars to enjoy. 

Yellow passionflower (Passiflora lutea) can be found throughout the arboretum. It isn't cultivated in any particular spot and volunteers freely. Sometimes we have to pull it off other plants, and sometimes we allow it to climb and twine. This time of year, its quirky little flowers are on display. In this photo, the passionflower vine is attached to a yaupon holly (Ilex vomitoria).

 Also, this summer, we have something extra special. Maypop!

 

Last year we planted Maypop (Passiflora incarnata), specifically during the spring of 2024. In this post from the autumn of 2023, we made clear our intent to do just that. It grew for a short time, but the Gulf fritillary caterpillars soon devoured all of the leaves, so the vine was not given the opportunity to climb or flower. Surprisingly, the plant wasn't killed by this premature defoliation; it started growing again this spring. And it is thriving! There are plenty of leaves for the caterpillars this year. The vine is attempting to climb an old eastern red cedar trunk.

In late July, we are seeing the peculiar "spaceship" flowers, and still no sign of the Gulf fritillary caterpillars. Perhaps these vines will even produce fruit this year. If you've never had maypop fruit, you've missed out on something special! Yum!

Gulf Fritillary (Agraulis vanillae)

Gulf fritillary butterflies (Agraulis vanillae) are abundant in the arboretum this month. How many Gulf fritillaries do you spy in this photo?

Here we see one fritillary sitting still and another one on the move.

The inside of the wings contains a gorgeous pattern reminiscent of stained-glass.

A second look at the crispy leaves reveals a fritillary!

This fritillary is in the weeds. We see some passionflower (Passiflora lutea). Do you know which vine is the passionflower? Passionflower is its larval food.

To see our previous posts on the beautiful Gulf fritillary:

November 6, 2023 

September 17, 2018

Gulf Fritillary (Agraulis vanillae)

Since we have been studying the caterpillar of the giant swallowtail (Papilio cresphontes), we might as well look at another interesting caterpillar, this time an arboretum favorite. The Gulf fritillary has appeared on the arboretum blog more than once (here and here). Summertime brings an abundance of yellow passionflower (Passiflora lutea) to the arboretum and every summer the fritillary comes back to enjoy it.

 

In this photo, we see an orange and black caterpillar attached to a yellow passionflower leaf. Over the course of the summer, the passionflower vine entwined itself with the dewberry vines growing on the west side of Mickle hall—the same patch of dewberry where the giant swallowtail caterpillar was found eating the young leaves of the toothache tree.

Here we see the Gulf fritillary eating a leaf of the yellow passionflower. Currently, this is the only species of passionflower in the arboretum collection. We ought to make it a priority to plant purple passionflower (Passiflora incarnata) in the spring.

We briefly removed the caterpillar from its vine so that we could take a measurement. At the moment, it's less than an inch long.

It's small, but looks scary! Aren't those spikes marvelous? Never fear; it's all for show. Presumably this is to dissuade any would-be predators. This type of defense color pattern is a different tactic than the one exhibited by the caterpillar of the giant swallowtail.

By contrast, the caterpillar of the giant swallowtail is inconspicuous: it both blends in with its environment and looks like something you want to avoid eating or even touching: a waste product.

Yellow Passion Flower (Passiflora lutea)

The yellow passion flower vine produces pretty blue fruits that ripen in late summer and early fall. The photo above was taken September 19, 2020.

Yellow Passion Flower (Passiflora lutea)

 

Passiflora lutea produces inconspicuous light-colored yellow flowers. Flowers and immature fruits can be found on the vine throughout the month of August.

Passifora lutea is a dainty vine. Leaves, tendrils, fruits and flowers all possess a delicate, subtle beauty.

 

Gulf fritillary (Agraulis vanillae)

If you stop to examine the passionflower vines (Passiflora spp.) at this point in the season, you may be lucky enough to spot a fritillary caterpillar. These little fellows look fearsome, but the spikes are all for show.

This caterpillar is happily munching away on Passiflora lutea.

Here we can see two caterpillars, separated by instar (the stage of development), age, and size. The tiny bloke hatched not very long ago, while the bigger specimen is close to metamorphosis.

How many caterpillars can you spot in this clump of passionflower vine?

Summer Update: Fruits and Flowers

There are a handful of immature fruits on the strawberry bush (Euonymus americanus), growing in the shade of our on-site native sweetgum (Liquidambar styraciflua). When the capsules open, they should reveal bright red seeds (do NOT eat).

The drupes of the Georgia holly (Ilex longipes) are ripening.

We have been watching the Mexican plums (Prunus mexicana) this summer. Numerous fruits fell early, but the branches are still heavy with ripening plums.

The fruits of the arrowwood bushes (Viburnum dentatum) are almost black.

Here we have a Gulf fritillary caterpillar conveniently stationed on its obligatory food source: the yellow passion flower vine (Passiflora lutea). The vine isn't long for this world.

The creeping cucumber vine (Melothria pendula) is producing fruits. These are said to be poisonous, so don't eat these.

 

 

 

 

In the arboretum collection, we have two kinds of French mulberry (Callicarpa americana). One produces purple berries; the other produces white berries. Above, we have an individual that produces the white variety--these berries won't turn purple.

The Louisiana catchfly (Silene subciliata) may not actually catch flies, but it certainly does catch the eye! They provide a bold dash of color in the late summer landscape. This nice patch is growing under a white oak (Quercus alba).