Other similar structures were hanging, exposed on cliff face. White sap in one of the photos came from plant.

According to observation https://www.inaturalist.org/observations/10880784

"Ischnolepis natalensis (synonym of Petopentia natalensis)
Glossy leafed creeper with milky latex. Bulbous root structure, almost always epigeal, in leaf litter amongst trees in forest, often at kranz edges."

For additional information:

https://www.inaturalist.org/taxa/591890-Petopentia-natalensis

http://www.llifle.com/Encyclopedia/SUCCULENTS/Family/Asclepiadaceae/26558/Petopentia_natalensis

https://wildflowernursery.co.za/indigenous-plant-database/petopentia-natalensis/