Euphorbia tirucalli, or Pencil Cactus. Sap may be very toxic to some; handle c care.
It is a tough, no-care plant (other than handling) plant that needs very little water and moderate light. Very happy in clay and watered once a month or less.

Hi there
it could be a sun starved Euphorbia tirucalli (pencil tree or something)
they naturalize on the Canary Island but probably originate frome somewhere else.

you can root cuttings/ limbs after they dried for some days,
bye, Lin

Here is a link that might be useful: funny Euphorbia

These plants should almost come c an MSDS.
If you cut them, be careful not to get that sap on your skin- or worse yet in your eyes.They bleed like stuck pigs. Wash hands and arms after handling. Wear protective clothing and gloves.
They are originally from Africa.

Bleeding of the plant is stopped immediately if the cut is doused with water.

The latex is caustic on skin only to those who are sensitive to it (mucous membranes are different). Many have no reaction at all. I have never found the latex bleeding of any euphorbia to be much of an issue - I prune my pencil cactus as needed to get the puppy back indoors each fall.