Saturday, January 2, 2010

The Swan Plant: Asclepias physocarpa

Sanremo: la Citta dei Fiori 
 City of flowers in 1920

The 2010 New Year's Day Concert from the Vienna Philharmonic Orchestra which was broadcast last night was a real feast for the senses. Apart from the usual Strauss waltzes and polkas, the programme managed to include a ballet with costumes by Valentino, footage of cake and chocolate making and a journey by boat down the Danube. And then there were the flowers, thousands of them shipped in from Sanremo Italy. Included amongst the mainly orange and yellow roses, lilies and ranunculus was the seed pods of the Swan plant .It is given this name because the pods are somewhat swan shaped with an S-shaped stalk at the base and a narrow beak at the tip. Unfortunately this very decorative plant is regarded as a weed here and should not be grown. It is a species of Asclepias which are poisonous to stock and contain cardiac glycosides (calotoxin, calotropin and calactin). These same glycosides are found in the Monarch butterfly whose larvae feed on this plant. The larvae also feed on Nerium oleander so this can be more easily grown to attract this wonderful butterfly to the garden.

The Swan Plant , Ascelpias physocarpa

Monarch Butterfly, Danaus plexippus


  1. I had this plant . We call them balloon plants. They self seed and show up everywhere. They disappeared when we had the African snail infestation four years ago. So did the snails.

  2. We have this plant and the caterpillars which grew in our pot plant, I decided to let it grow to see what is was and now I have seen it here on the net. I had never seen any thing like it before, a friend at my ladies bowling club in Yamba told me what it was after I describe it to her even down the caterpillars.