The message
from "Colin Spooner" contains these words:

Hi There,
I have several Euphorbia varieties in my garden including E.Characis -
E.Mellirera - E.Martinnii - E Black Pearl.
Sorry if the spelling is wrong!

E. characias, mellifera, martinii.. (right spellings just in case
you need to google them) can all be cut right back hard and will come
again (youi may see tiny new buds down there already.)

Don't get the while sap on your skin, it can be irritating.

Janet