Aristolochia triangularis

Aristolochia is a family of plants with around 400 species that are spread over many parts of the world. They grow as either vines, which can produce many metres of growth, or as herbaceous plants. There are some Aristolochia sorts that have tuberous roots, such as A. fimbriata, but the majority do not. The leaves are heart-shaped and the flowers are not unlike Ceropegias. They are pollinated by flies which are trapped for a day or so and then released to fly to the next flower.

A free-flowering species that is easy to grow, producing many metres of growth in one season, is Aristolochia triangularis. The leaves are large, often hiding the flowers. The seed is produced in small capsules with several seeds in a pod. Propagation is either by cuttings or seed. The seed takes about 2 or 3 weeks to germinate. So far, my plant has not been attacked by any pests or diseases, but I have only grown it for two or three years, so I have no long-term information to give on this point.

The plant occurs naturally in Northern Africa, Western Asia and South-Eastern Europe and may very well be winter-hard in slightly cooler climates, but I have not grown it outside myself, so no guarantees. In the winter, I keep it at 10°C in a greenhouse and only bring it outside when the frost is over.

Aristolochia triangularis

 

Periploca graeca

In the latest Asklepios, number 110, there was a very interesting article about Periploca graeca, a vigorous climber. This plant is one I have owned for many years and it grows extremely well outside here in the Netherlands, taking all that the weather can throw at it. It has survived temperatures down to -10°C.
My plant was removed from our garden at home and replanted at the nursery. Some root fragments must have been left behind, because there is now a smaller plant growing on the original spot which suggests that this species can be propagated by root cuttings. But I prefer to take stem cuttings which root fairly easily.
The plant flowers extremely well, producing hundreds of flowers every year, but no seed at all. It could be that I need a second clone of this plant or that the insect pollinator is not present in The Netherlands. The plant is available from specialist nurseries and can be added to the few species of asclepiads that can be grown outside in all weather conditions.
 
Link to the Asclepiad Society

Periploca graeca