Butterfly vines and Swallowtail butterflies

We have been growing a particular vine, for years, just for the Birdwing butterflies whose caterpillars depend on it. Just what the vine is called and which butterflies depend on it are, however, recurring questions – for us as well as for the many other people who love the butterflies. This post pulls together information from botanical and entomological books and websites to try to settle both questions.

Very briefly, all species of butterflies in one group of Swallowtail butterflies have specialised to feed exclusively on one group of closely related plants. The butterflies are the Troidini, a “tribe” (in scientific language that’s a level between “family” and “genus”) of Swallowtails (Papilionidae) and the plants are the Birthworts (Aristolochiaceae).

Our Troidini are the Clearwing Swallowtail (Cressida cressida), Red-bodied Swallowtail (Atrophaneura polydorus) and all of the Birdwings (Ornithoptera species). The Aristolochiaceae we’re interested in are in the genus Aristolochia, or used to be, and many of them are known as Dutchman’s Pipe vines.

caterpillars of clearwing and birdwing butterflies
Caterpillars of Clearwing (left) and Cairns Birdwing butterflies, both nearly fully grown, on Aristolochia tagala

Everything gets messy at the next level of detail. If you want to avoid that but still attract the butterflies to your garden, this is all you need to know:

  • Aristolochia tagala, also known as Aristolochia acuminata,  is a food plant of all our Birdwing species and of the Red-bodied and Clearwing Swallowtails, and it is the one most widely grown in Townsville gardens. It is sold by the Bush Garden Nursery as A. acuminata.
  • Richmond Butterfly Vine, Pararistolochia praevenosa, is a food plant of all  Birdwing species and the Red-bodied Swallowtail. It is the vine widely promoted in SE Queensland as the “birdwing butterfly vine.”
  • Dutchman’s Pipe Vine, Aristolochia elegans also known as A. littoralis, is the one to avoid. It’s an exotic, introduced from South America, and it poisons our butterflies. The adults lay their eggs on it but the caterpillars rarely survive.
  • If you stick to the Latin names, there should be no confusion about which vine is which.

Here are the flowers of the three vines:

Aristolochia flowers
Three pipevines, from the Butterfly House site

Why and how do scientific names change?

Latin names of every species from fleas to cassowaries and from oregano to mountain ash are usually given as two words, Genus species, and organisms are formally named by the first person to fully describe them in a scientific publication. If there are slight variations within the species, it might be divided into subspecies, so the name is lengthened to Genus species subspecies. That’s clear enough, of course, but then someone else comes along …

  • If one genus appears to be too similar to another, they can be merged under whichever name came first; in that case, all species (second) names stay the same.
  • If some species in one genus are seen to be too different from each other, the genus can be split; some organisms will get a new genus (first) name.
  • If some subspecies begin to look different enough from others, they can be promoted to species ranking; they will lose their middle name.
  • It may be noticed that the same organism has been described and named twice; the first name is given priority and the other, the “synonym”, is (gradually) abandoned.
  • Similar changes can be made at higher levels of classification, such as  Family, Superfamily and Tribe, but they are not as common.

This blog has discussed these sorts of changes in relation to the Koel and Melaleucas, among others, over the years. They don’t happen very often to any one species but with millions of species to look out for, keeping track of the names is a big job; see, for instance The Plant List.

There are, of course, no limits or rules on common names.

The butterflies

The simplest way to sort out the butterflies is to quote the list given on the Butterfly House site and add alternative names to it as required. Links lead to species pages on that site, with photos of adults and caterpillars, so following them should resolve any uncertainties.

Braby comments that, “Much confusion and controversy has surrounded the taxonomic status,” of our Birdwings. He lists them all as Ornithoptera, mentioning that they were previously known as Troides. (Troides has recently been split into Troides, mostly Asian butterflies, and Ornithoptera.)

Braby divides Ornithoptera into only two species, priamus and richmondia, but divides priamus into four subspecies, calling the Cairns Birdwing Ornithoptera priamus euphorion. Others have named as many as 19 subspecies, while Wikipedia : Birdwing takes a middle position, listing three Australian species (euphorion, priamus and richmondia) under Ornithoptera.

The Richmond Birdwing lives so far South of any of the others, in a small coastal area near the Qld-NSW border, that it can’t be confused with them. The other/s have a patchy coastal distribution from Mackay to Cape York, new Guinea and the Pacific islands, and the debate over their names is really about whether local differences are big enough to justify calling them subspecies or species.

What all that means to us is that anything called either Troides or Ornithoptera but not richmondia is one of our NQ Birdwings and it is very closely related to all the others. Since they all look so similar and all feed on the same plants, that’s not a bad outcome. “Cairns Birdwing” is probably the least controversial common name for them.

The vines

Aristolochiaceae includes both Aristolochia and Pararistolochia. Species in the latter were included in Aristolochia until the genus was split in 1996, so many older references will still have, for instance, Aristolochia praevenosa rather than Pararistolochia praevenosa. There are hundreds of species in these two genera worldwide but fortunately we are only concerned with a dozen of them.

Here’s a composite list based on the Butterfly House site but cross-checked with Braby’s book and a list prepared by Peter Valentine. The first two are the most important to us because they are the most readily available.

  • Birthwort, Aristolochia tagala also known as A. acuminata.
    If anyone uses a common name for it, it will probably be “Native Dutchman’s Pipe”, but really it is better to use the Latin name. This is a food plant of all Birdwing species and of the Red-bodied and Clearwing Swallowtails and it is the one most widely grown in Townsville gardens. It is sold by the Bush Garden Nursery under the name A. acuminata, a synonym of A. tagala.
  • Richmond Butterfly Vine, Pararistolochia praevenosa.
    All Birdwing species and the Red-bodied Swallowtail. This is the vine widely promoted in SE Queensland as “the birdwing butterfly vine”.

These other native (i.e., good) species are all listed for some of our butterflies but not for all of them. However, the differences seem to be mainly geographical, e.g., the vine can’t be listed for the Richmond Birdwing if it only grows on Cape York.

  • Mountain Aristolochia, Pararistolochia deltantha
  • Indian Birthwort, Aristolochia indica
  • Chalmer’s Birthwort, Aristolochia chalmersii
  • Australian Native Dutchman’s Pipe, Aristolochia thozetii
  • Cairns Birdwing Butterfly Vine, Pararistolochia australopithecurus
  • Heathlands Aristolochia, Pararistolochia linearifolia
  • Cape York Birthwort, Pararistolochia peninsulensis

Most of them are rainforest plants and several have alternate names. Aristolochia thozetii and Pararistolochia deltantha are  worth special mention in that they are local (well, Paluma Range) and have attractive flowers so they might be candidates for home gardens or revegetation projects.

These last two are listed only for the Clearwing:

  • Holtze’s Birthwort, Aristolochia holtzei
  • Hairy Birthwort, Aristolochia pubera

The villain

  • Dutchman’s Pipe vine, Aristolochia elegans, also known as A. littoralis.
    This is the one to avoid! It’s an exotic, not a native, and it poisons our butterflies. The adults lay their eggs on it but the larvae usually don’t survive.
    Brisbane City Council calls it a weed and describes it fully on this page and, at the bottom, lists other exotic Dutchman’s Pipe vines which are not (yet) such a problem but should be avoided for the same reasons.

4 thoughts on “Butterfly vines and Swallowtail butterflies”

  1. The more you know, the more there is to learn, they say!

    I’ve just looked up Aristolochia indica, after trusting the Butterfly House site’s word that it was okay and being gently queried on it by my Friendly Local Expert.

    The Butterfly House people do call it “Indian Birthwort” but don’t actually say it’s introduced. This ANBG site says it is an “introduced species originally from India to Malaysia, now naturalised in NT. … Grows in monsoon forest. … Apparently only naturalised on Channel Island, Darwin Harbour, N.T.”

    Wikipedia, meanwhile, says, “This plant is critical to the survival of the [Indian] southern birdwing and common birdwing, as well as crimson and common rose butterflies,” which are close cousins to our own birdwings and swallowtails. This led me to believe that it is probably okay for ours as well, and Sankowsky’s new butterfly book confirmed that when I checked.

    At this point I’m going hazard a guess that Asian and Indian Aristolochias might all be okay and the South American ones not, just on evolutionary closeness, but it’s just a guess. The more you know, the more there is to learn.

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