African Wildlife & Environment Issue 83

FAUNA, FLORA & WILDLIFE

lepidopteran larvae (NOT browsing mammals). When ants find a tasty morsel they remove it to eat. Thus protecting the growing shoot! The photo below is a close-up of the ENF on a primary leaf’s petiole. Note that it is oblong and that there is a pit in the centre. If you are VERY lucky you may even be able to find a tiny sugary

Above a PRIMARY leaf- determined as at the node exactly between the stipular spines. Here it has just two pairs of pinna-that is usual in more arid areas, while in moister areas there are usually more pinna pairs (4-8/10). In arid areas secondary

droplet sitting on the gland (that has been exuded overnight – we got one photo in the lab at UWC that I have somewhere). Below are three leaves that are from left-to right primary, axillary and secondary (forget about axillary for now and maybe forever for this essay!?). Maybe not 100% clear in my photo is the fact that on the petiole of the PRIMARY leaf there is an EFN and that the petiole groove is SHALLOW. On the SECONDARY leaf’s petiole there is no ENF and the petiole is deeply grooved! To me “grooving” is MUCH better represented on

leaves usually have one, possibly two, pinna pairs and in moister areas there may occasionally be as many as four. Thus another way to separate primary and secondary leaves is by pinna pairs. Not the greatest photo but it does show an ant visiting the ENF of a primary leaf. You most often get these ants on VERY young shoots that are still “sticky” themselves – so most common seasonally, when the plant is actively growing its shoots of unlimited growth. My take on this is that the plant encourages the ants with a sugary reward to wander round the growing apices because the PRIMARY herbivore that attacks the young shoots of unlimited growth are

27 | African Wildlife & Environment | Issue 83 (2023)