A thicket of Cotoneaster, some shrubs over 2m wide and 3m tall and African olives close by: I hit the jackpot.
27. 04.2016: Four large multi-stemmed Cotoneaster and numerous small plants are hopefully dead after > 6 hours of hard work.
Cotoneaster pannosus has larger but thinner leaves and fruits in bunches rather than the small thick leafed C. rotundifolius which has fruit in ones or twos along the stem.
Michael, many thanks for the id. I had a hedge of those in my garden not long time ago. I think to remember in the CIT horticulture course we students were told that C. rotundifolius is not invasive...