Common names: Dutchman’s Pipe
In my December Notes I mentioned the large number of seeds that had been left in the soil when we cleared out these vines. Thousands of these seeds have now germinated and they completely carpet many square metres of bushland. Spraying with a herbicide will be the only viable solution. I can only hope that the recent wet weather has caused most of the seeds to germinate so that we don’t have to face this problem over and over like we do with the Rivina humilis (Coral Berry).
Our last few working bees have focused on clearing the area below the southern side of the picnic ground. The main reason for this is to clear the severe infestation of Aristolochia elegans (Dutchman’s Pipe) creeper. This species is a declared class 3 pest in Queensland. It grows vigorously and smothers understorey trees and shrubs. Some of the creepers that were growing here had stems that were 4 cm in diameter and these vines carried dozens of old mature seed capsules that had already released their seeds onto the ground. It is possible that this patch of plants has already released 100,000 seeds! I suspect that this means that we can look forward to several years of serious weeding in this area to eliminate this pest from the reserve.
As well as smothering native vegetation, this weed is also toxic to the larvae of Richmond Birdwing (Ornithoptera richmondia) and Clearwing Swallowtail (Cressida cressida) butterflies. If these butterflies lay their eggs on the Dutchman’s Pipe vines the larvae die before they reach maturity (unless the larvae feed only on the flowers). The photo below shows their spectacular flowers and an empty seed capsule that contained many hundreds of flattish heart shaped seeds.