I get asked regularly 'what is that tree out the front?' of the property where I work, and never seem to get around to identifying it.
But it should be a snap for you.
I believe it is South African. Mega tall, thorns all the way up its trunk, & has single flowers with dark pink petals. One client thought it started with 's' & is a singa or something.
I don't have a pic ATM but will try & remember to get one next week.
Thanks FM.