I had a discussion, with PM, long ago, about whether the plant I had was the one used in asian cooking or the one they chew in PNG.
Someone has messaged me through Ozgrow wanting to get a cutting, if it is in fact P. sarmentosum. They’ve just returned from a trip to Thailand where they used it in a cooking class. To help me ID mine they sent me this link.
http://thaifoodandtravel.com/blog/betel-leaf/
So it looks like mine is the culinary one after all.