First thing to say is that generally spreaking a weed is a plant in the wrong place. Now, your plant is a Euphorbia, can never remember its full name, but to me at least it is a terrible weed. A weed because it seeds itself all over the garden where it is not welcome.

Thanks will pass that on and let them decide.

Caper spurge, euphorba lathyris, often seeding in gardens. The mature plant is about 4 - 5ft tall. The seed cases explode with an audible 'click' to release the seeds. Beware of the sap, it can cause rashes, and is mildly poisonous. DON'T RUB YOUR EYES AFTER HANDLING IT! I did, and it really really hurts. Phil J

cracking fuchsia crouching demurely there in the foreground though.