Inflated stipular spines of Acacia cornigera and other acacia species are natural homes for mutualistic ants that protect these plants from herbivores. A pair of stipular spines forms at the base of each bipinnately compound leaf, and the leaves have the yellowish Beltian bodies, which provide a reward for the ants that attack their home. The woody spines are also extremely useful in preventing many grazers from eating the shoots, but cannot stop beasts like elephants, which can easy crush the material without consequences from the ants.

[Return to Text]