Experiments

THE WONGAN ‘CACTUS’ (Daviesa euphorbioides) PROJECT

Participants: Joe Holtum (JCU), Lillian Hancock (Bio-Logic), Kings Garden staff (Perth)

Project: Daviesa euphorbioides is a cactus-like critically endangered native legume (Fabaceae) from Western Australia. CAM is well-known in the Cactaceae but has not been demonstrated in the Fabaceae. Lilly Hancock and I tested the so-called Wongan ‘cactus’ for CAM by measured dawn and dusk titratable acidities in plants growing outdoors at Kings Park and Botanic Garden, Perth, WA.

Progress: The data were tantalising but inconclusive. Acid levels were greater at dawn than dusk, as expected for CAM, but the levels were low and the differences were not statistically significant at the 5% cut-off. We tested only a small number of samples because of the limited amount of plant material that was available of this critically endangered species.