Thanks first of all for your active participation in the plant guessing. Attached is a closer picture. I would say the spikes are with Yvonne? Still find it difficult...
If I knew who lives there, I would have done it already.
We are in a large apartment complex and it is a different building. I would have to ring the doorbell throughout the house to find out who it is, and with the current weather, no one is hanging out on the terrace.