Agelanthus kayseri is a species of hemiparasitic plant in the family Loranthaceae, which is native to Kenya, Tanzania and Somalia.
A description of the plant is given in Govaerts et al.
A. kayseri is found in coastal bushland and mangrove stands, extending inland along rivers, commonly on Dobera, Salvadora or mangroves, based on Polhill & Wiens.