The Pipe-dream Project

(Pipe-dreams are “fanciful or unrealistic hope or plans.” We hope to show that even pipe-dreams can come true!)

By Jeff Glassberg

The following article originally appeared in American Butterflies (Vol 9: No.2, Summer 2001).The names of plant species are even less uniform than are butterfly names. In this article, the author has chosen to call all species in the genus Aristolochia, pipevines. Plant books apply the same name – Dutchman’s pipe – to many species and may use different group names, such as calling A. serpentaria Virginia Snakeroot.

Pipevine Swallowtails, with brilliant blue flashing wings, inhabit much of the United States, although in many areas they are quite scarce

The caterpillar food plants for Pipevine Swallowtails are pipevines, plants in the genus Aristolochia. Many of the pipevines make good garden plants and they were very popular in Victorian times. In fact, pipevines were so popular that the range of Pipevine Swallowtails expanded northward as this new food source became available.

Now, NABA would like to increase both the numbers and range of Pipevine Swallowtail. We believe that just as placing nesting boxes for bluebirds has led to a resurgence of that species, people can greatly help Pipevine Swallowtail by planting pipevines.

Pipevine species that are native to the United States.
Although, of course, there are various opinions, there seem to be eleven species of pipevines native to the United States (To the best of my knowledge, none occurs naturally in Canada). Some of these species are available from various native plant nurseries across the country. A few will be mentioned later in this article, but for now, you can search on the web for potential suppliers. We encourage you to select species that are native to (or occur close to) the area where you live.

• A. macrophylla (previously A. durior) (Dutchman’s pipevine). This is a large-leaved eastern species that makes a wonderful garden plant. It is a woody vine that thrives in partial sun and will climb arbors or other supports. Native from southern Pennsylvania to Georgia (in the mountains) and west to Minnesota and Kansas.
• A. tomentosa (Wooly pipevine). This small downier version of A. macrophyllaoccurs from North Carolina and Missouri south to the Florida Panhandle and Texas.
• A. serpentaria (Virginia pipevine). This small, inconspicuous and often overlooked species grows to 2 feet tall from an underground stem. The “pipe” flares at the end into a brownish-purple, slightly three-lobed disk. It blooms mainly from May to July in woods from Connecticut to Illinois and Kansas and south to Florida and Texas. In the garden it prefers a well-drained loamy soil, rich in organic matter, in sun or semi-shade, but succeeds in ordinary garden soil.
• A. convolvulacea. A woodland species found from North Carolina to Georgia.
• A. pentandra (Marsh’s pipevine). An herbaceous vine found in the hammocks and keys of extreme southern mainland Florida and the Keys (endangered) and south Texas.
• A. reticulata (Texas pipevine). Found in East Texas (mainly pinewoods), Arkansas, Oklahoma and Louisiana.
• A. erecta (Swanflower pipevine). A Texas species.
• A. coryi (Cory’s pipevine). A Texas species found in the Trans-Pecos and Edwards’ Plateau.
• A. wrightii (Wright’s pipevine). Found in Trans-Pecos Texas and New Mexico.
  A. watsoni (This account by Jim Brock). Found from West Texas to southern Arizona, this species is found mostly in grassland or sparse woods between 2500 and 4000 feet in elevation. The leaves are triangular, green to purple and generally smaller than the leaves of its tropical relatives. The flower is small and fairly inconspicuous. In fact, the plants can be difficult to locate in the field owing to its overall small size.
  Propagation is not difficult but the seeds require two years for germination. Not realizing this most people give up after the first year believing they have bad seed. Once established the plant will produce trailing stems from a thick root. See the last issue of American Butterflies for illustrations of this plant.
• A. californica. Native to the northern California Coast Ranges and the foothills of the northern Sierra Nevada, this woody vine is capable of strong climbing and makes an attractive garden plant. Bloom period is mainly January through April.

In the last issue of American Butterflies we asked members to share their experiences with pipevines. Here are some responses.

From S. Coates, Brooklyn, New York

I planted a pipevine (A. macrophylla) in my backyard in Brooklyn, New York last spring. In a single season, it grew in height from a foot or so to about 20 feet, trailing up the deck at the back of my house. Right now, it is just about to sprout new leaves from the old growth, and presumably, continue its march.

I hoped eventually to attract Pipevine Swallowtails, which I knew to live in New York City. But in that very first summer, I discovered three clusters of yellow eggs, laid characteristically on the plant’s leaf stems. This was a bit of a surprise, since I had never seen Pipevine Swallowtails in my backyard. In any event, she easily sniffed out my plant.

Two or three days after most of the eggs had hatched and the caterpillars had all moved in their gregarious way onto the nearby leaf surfaces, New York City sprayed my neighborhood for mosquitoes [as part of its misguided anti-West Nile Virus campaign. Ed.], and by the next evening, not a single hatchling was left on the leaves. I am eagerly watching to see if I get more eggs this summer.

I bought my original pipevine by mail order from Roslyn Nursery on Long Island. Last fall, I planted four more vines and gave a couple to neighbors, for good measure. I also plan to donate a few to local community gardens.

There’s a lot to be said for Dutchman’s pipevine, even butterflies aside. It is a native plant that was popular in gardens during the Victorian era because its wide, thick leaves were excellent for shading. It will grow faster and thicker in sun, but is a good shade plant, too. Its flowers, pale yellow with purple to dark brown eyes and shaped like old-fashioned clay pipes (hence the name), are unusual and appealing to gardeners with a bent for the out-of-the-ordinary; there’s an Aristolochia discussion group on the Internet, and the vine is often featured in books about old-fashioned plants. In horizontally-challenged urban gardens, it should be a natural for climbing trellises and covering fences as a privacy screen. As far as I know, it doesn’t require any special care.

One caveat: I am told that the caterpillars are extremely voracious, which could present a problem for gardeners first trying to establish vines, should the butterflies find them early.

From R. Smith, Plymouth, Michigan

Last year my friend and I attended a talk about “Butterfly Gardening.” The speaker mentioned the scarcity of Pipevine Swallowtails in Michigan lately and asked people to plant pipevines to try and help them out. Needless to say we both planted pipevines in our gardens.

It was a fascinating experience. We found eggs shortly before I was to leave on vacation. There were thriving caterpillars by the time we did leave…but boy did they eat! I had a neighbor caterpillar-sit (although she wasn’t too happy tending the little critters). Not wanting to be un-neighborly, she did not tell me of her apprehension at putting her hands in the aquarium. When we came back the first thing I did was race in to check on the Pipevines and was horrified at what I found. 4 large caterpillars had converged on a hanging chrysalis and had already eaten half of it. I was so upset I almost cried at the sight. After all my careful work nurturing them they had turned to cannibalism to survive. The aquarium I’d left with plenty of leaves held only stems’ and two withered green leaves. My friend had assumed that since they were green there was still food. Unfortunately the stems’ were lifted out of the water and they were no longer edible.

I quickly rushed to the pipevine plant outside and cut more leaves’ for them. Once the caterpillars found the fresh greens they did not seem to care about anything else. One by one they each formed a chrysalis and all went well. By this time it was nearly fall and we were hoping our butterflies would overwinter and wait until spring to emerge (since it had turned quite cold at night). They nevertheless started emerging. They were gorgeous! All our efforts had turned out the most beautiful butterflies you could want.

From E. Williams, New York, New York

I just received my American Butterflies magazine and saw the article about Pipevine Swallowtails. I was amazed that there was an article about the very butterfly that captured my imagination and interest last summer.

We have a weekend home in Ulster County, New York with lots of butterflies. I became more interested in them about two years ago and have been keeping records of those I see. Four years ago I planted a pipevine (A. macrophylla ). I got it to cover a trellis near the house to provide some shade. I also hoped that it would attract Pipevine Swallowtails. The vine took a long time to become established, taking three years to reach the top of the trellis.

Last summer (the vine’s fourth summer) I was thrilled to find Pipevine Swallowtail eggs and caterpillars — three separate broods. But, my experience was very much the same as Jim Brock’s. The caterpillars all disappeared before they became mature!
My caterpillars were the black ones with the orange bumps. I noticed that the red spines and long feelers of the caterpillars looked a little like a dried-up pipevine flower. Could this be a reason for the two color phases? Do they appear on different species of pipevines?

In September, we went on vacation and upon our return, I searched the vines but could find no sign of the caterpillars or of eaten leaves. Were they all eaten? Or, did they go somewhere else? As Jim Brock did, I wonder why, if they are supposed to be so poisonous, these caterpillars apparently were eaten.

How did the adults find my vine? How far did they have to come? Also, I wonder why the caterpillars eat the new leaves and shoots. It seems that these would contain fewer toxic secondary compounds than the older leaves. Perhaps the young caterpillars have to work up gradually to ingesting the toxins, and were eaten before they got a chance to do so.

From C. Pearson, Dearborn Heights, Michigan

I planted a 6 inch tall pipevine 4 years ago next to one post of a pergola. By the end of last summer it had grown up about 8 feet, into an apple tree. Last year it bloomed for the first time with two flowers. I have seen no Pipevine Swallowtails so far but it has an exotic appearance with its large leaves. Once it gets established it needs no care. Mine is on the east side of the house where it gets morning sunlight.

From R. Roscioli, Easton, Pennsylvania

Over the course of several years that I have lived in a semi-rural area near Easton Pennsylvania, I had seen only two Pipevine Swallowtails on my several butterfly bushes. Both were in good condition, and one was very fresh. I figured they couldn’t have traveled far to get here, but I knew of no local populations or of any food plants nearby. I had an idea that if I planted pipevines maybe I could draw more in and possibly start a breeding population here.

I now have two areas in my yard where several vines are growing, even producing flowers, but as yet have not seen any caterpillars or eggs, but last year did see at least one other Pipevine Swallowtail on the bushes, nectaring. I do think this is a good idea to try to increase both the numbers and range of this butterfly, especially since I thought of it on my own. But, why stop here. Lets plant fennel, parsley, paw paw, and any other food plant that might be practical for a given location.

From C. Small, Beverly Hills, Florida

It took me three years to get a Pipevine Swallowtail on my plant. It is the Dutchman’s pipevine with the large leatherlike flowers. I have checked many local nurseries and never found any eggs or caterpillars on their plants. Perhaps they spray. This spring, I noticed the smell of the dead leaves of my plant. I really feel that the butterflies can smell this plant from a distance.

From S. Dees, Springfield, Illinois

It was with great interest that I read the article by Jim Brock in the Spring 2001 American Butterflies and even greater interest about the Pipe-dream Project! Pipevine Swallowtail is my favorite butterfly species and is not well known in my area (Springfield, Illinois). My childhood nature mentor grew pipevine (A. macrophylla) and had a resident Pipevine Swallowtail population in her yard, and it had been my dream to do the same thing. After her funeral, a few of us were invited to dig up some favorite plants from her yard — I got the pipevine.

I have had a yard colony of the plants (one A. macrophylla and mostly A. tomentosa) and butterfly for the past 5 years, after starting the pipevine 9 years ago. It took several years to reach population equilibrium between the butterflies and the plants. After allowing the plants to grow for several years, I introduced the butterfly. At the beginning I reared wild-caught caterpillars and released them as butterflies. Then I captured a mated female and she laid about 50 eggs in captivity. I released her and then reared the caterpillars, later releasing them as adult butterflies. That year there was a butterfly overpopulation, which of course led to caterpillar starvation after they stripped my vines, and an ensuing reduction in the butterfly population. On most days I can wander the yard and find one or more of the butterfly’s life stages. I usually get about 3 broods of the butterfly per year. Last summer the A. tomentosa bloomed, but has never set seed. If you could publish some information about encouraging bloom and seed-set, that would be great. I have grown this species easily from seed in a pot and then planted the seedlings into the yard successfully. Illinois also has A. serpenteria, and I had moved a very robust plant of that species to my yard from a highway construction site. However, I am not sure my plant still remains. It got chewed down to ground level during the first year or two of the butterfly overpopulation and I am not sure it recovered.

For the past few years, I have been actively proselytizing my local nature nut friends in central Illinois to plant our native Illinois pipevine, A. tomentosa, to attract Pipevine Swallowtails, and I have been supplying them with seed. When people see how beautiful the butterfly is, they are more than willing to plant pipevine.

From P. DeSimone, St. Petersburg, Florida

I’ve been growing Aristolochia elegans [a tropical species] in a large pot (with a trellis) for two years. The first year brought no butterflies. But last September I found caterpillars! Although I hadn’t seen the adult butterfly I assumed the caterpillars were Pipevine Swallowtails. I raised ten caterpillars. Imagine my surprise when they emerged — they were Polydamas Swallowtails!

L. Willis, Soquel, California

I live in Santa Cruz County in California where A. californica no longer grows wild. I have propagated it successfully by layering in the summer, by stem cuttings in winter and by seed. Growing from seed is quite easy if you can find a source. The plant seems slow to establish. Mine have grown little after two years. Established vines, however, grow rampantly. Although California pipevine needs little water once established, with added water it is more luxuriant and has more flowers. It grows best in part shade and needs something substantial to climb. I think it is an interesting plant, well worth growing for its own sake as there are no Pipevine Swallowtails here (yet). I hope that your campaign will increase interest. Do you plan any publicity other than your magazine? Articles in other publications or perhaps color posters for use at arboretum and native plant society sales would be a big help.

From J. Prentiss, Corpus Christi, Texas

I like your idea of increasing the range of the Pipevine Swallowtail by extending the food plants of the caterpillars. It should work.

I have had very good success with the pipevine species Aristolochia fimbriata [a tropical species]. I live in Corpus Christi, Texas and have raised as many as six broods in one season(April-October) on this plant. The reason you can get so many broods is because of the plant’s fast recovery period. It grows very fast when fertilized and watered regularly. By the time one brood is ready to emerge, the plants are ready for another onslaught of egg laying. The caterpillars use the whole plant; all the way to ground level.

A. fimbriata also makes a good garden plant in either pots or hanging baskets. It has pretty leaves, unique flowers and interesting seed pods. It is cold sensitive but begins to leaf out in early Spring. Another plus is that it is also an excellent food plant for Polydamas Swallowtail caterpillars.