ARISTOLOCHIACEAE

The Aristolochiaceae, also called the birthwort or pipevine family comprises some 400+ species of tropical climbers or shrubs. They are easily recognised by virtue of their bizarre pipe-shaped flowers, which are conspicuous and bad smelling. Aristolochiaceae flowers have evolved to attract and capture insect as pollinator. They have long been inspiring to Western herbalists who endorsed the doctrine of signature (like cures like). Aristolochia in Latin literally means ‘best of birth’. That's because herbalists think that Aristolochia flower looks like human uterus, hence beneficial for post-partum women! Perhaps by coincidence, Aristolochiaceae are also prevalent in traditional Chinese medicine. This combination made Aristolochiaceae one of the deadliest poisons due to human consumption by ignorance. All Aristolochiaceae contain a group of alkaloid toxins called aristolochic acids, which are strongly nephrotoxic (poisons the kidneys) and carcinogenic (cancer causing). Aristolochic acids permanently bind to human DNA, inducing harmful mutations that lead to cancer. Tens of thousands of people have died of cancer, or suffered permanent kidney damage following long-term consumption of herbal remedies containing Aristolochia. As a slow acting poison found in unregulated herbal remedies, Aristolochiaceae continue to threaten public health today.

Remarkably, one group of insects, the swallowtail butterflies (Troidini) have evolved resistance to aristolochic acids. Swallowtail caterpillars consume nothing else except for a particular species of Aristolochia. They steal aristolochic acids as defense against predators. The National butterfly of Malaysia (Rajah Brooke birdwing) and Singapore (Common Rose) both harbour this unique relationship with Aristolochiaceae.

Genus Aristolochia

Indian birthwort (Aristolochia indica). Native to India and South Asia.

 Aristolochia acuminata (syn. Aristolochia tagala). Native to Southeast Asia.

Gaping Dutchman's pipe (Aristolochia ringens). Native to South America. South American Aristolochia spp. tend to have larger more impressive flowers, hence cultivated as tropical ornamental plants.

Aristolochia ringens, close up of flower.

The pelican pipevine (Aristolochia grandiflora) is native to South America. It produces one of the largest Aristolochiaceae flowers. The flower emits a powerful scent of rotting corpse to attract flies as pollinator.

Aristolochia grandiflora flower, lateral view.

Aristolochia grandiflora, close up of flower.

The ridiculous Dutchman's pipe (Aristolochia ridicula) bears some of the weirdest looking flowers of any plants! This species is unusual because it is very pubescent (hairy).

Aristolochia ridicula, pre-bloom.

Aristolochia ridicula, close up of flower.

Aristolochia ridicula, lateral view.

Aristolochia ridicula, close up of 'mouth'.

Genus Thottea (Tree Pipevines)

The genus Thottea comprises some 43 species of shrubs and trees endemic to the rainforests of Southeast Asia. Thottea is so named after a Danish count and book collector, Otto Thott. Thottea spp. are usually hardwood shurbs or trees with less conspicuous flowers. They produce string like seedpods containing winged seeds.

Thottea piperiformis is a hardwood shrub or tree that is native to Southeast Asia. It is an important host plant for many swallowtail butterfly species.

Thottea piperiformis, close up of seedpod (red arrow).

Thottea piperiformis, foliage and flower.