ASSOCIATION OF SOCIETIES FOR GROWING AUSTRALIAN PLANTS
HIBISCUS AND RELATED GENERA STUDY GROUP
REQUEST FROM GEOFF HARVEY FOR INFORMATION
INTRODUCTION
Native hibiscus, especially Hibiscus heterophyllus and some introduced/naturalised species of hibiscus have long been used as a food source in this country. I have become aware from a Study Group member that there is a perception in the horticultural/landscape industry that Hibiscus heterophyllus is a poisonous plant. I consider that this is a serious misconception. As a Study Group, I believe we should address the question of safety in Hibiscus, particularly Hibiscus heterophyllus, both as bush tucker and in modern usage. Suspected toxic levels of oxalates in young and old leaves is a particular issue that needs to be examined.
POSITIVES
Many web references tell us that native hibiscus are edible, particularly the flowers. Other references mention roots and the leaves. Some Study Group members make and enjoy drinks, syrups and jams made from the blooms of Hibiscus heterophyllus and its crosses. I frequently chew up a leaf of Hibiscus acetosella or Hibiscus heterophyllus, when in the garden, with no adverse reactions. I like the tangy, acid flavour that I find refreshing.
NEGATIVES
Given the coarse, fibrous and prickly nature of Hibiscus leaves, it seems unlikely that anybody would consider consuming mature Hibiscus heterophyllus leaves, especially in quantity. However, given the following online references to eating the leaves (or tea derived thereof) of Hibiscus heterophyllus, the assumption that the leaves, whether young or mature, contain a high level of soluble and/or insoluble ??oxalates needs to be addressed urgently.