The channelled, ascending leaves of Pteronia fasciculata seen here, yellowed by a long dry summer, are sessile (stalkless), overlapping on the stem. Their margins are ciliate; the fringe of tiny, short hairs bears comparison to eyelashes.
The spider settled in among the leaves may not have picked such a good spot for making a living. It appears to be quite dead. White spiders are often crab spiders, but some dead ones may turn ghost-like. (Comment added as a service to the suggestible ones keen to believe way out, unproven stuff).
Crab spiders come in different colours like blue, white and yellow, able to blend with their surroundings. They have legs of different shapes and sizes, the front legs bigger than the back ones, making them crab spiders. There are the usual eight legs of members of the spider family, but in their case also eight eyes that will spot you.
Crab spiders are harmless to people. They hunt pollinating insects. The family of Thomisidae that includes them comprises about 3000 species (www.africansnakebiteinstitute.com; https://badpests.com).