Purslane is very common in Greek Diaspora salads in Canada and the United States, too.
I sometimes see newcomers from Greece or the Middle East collecting it, as well as wild dandelions, and other greens. I don’t really consider it foraging, when I see people collecting greens and herbs in a park where the lawn is cut by a lawnmower, or on the side of the road, in or near a city.
Our North American cities and farms currently spray a lot of herbicides on weeds. I wouldn’t be eating any purslane or other edible weeds growing along the roadside or in parks in my region. There are some highly invasive portulacas, so I would not introduce it to my veg garden. One type of invasive portulaca is known as pigweed in my region.
That said Common Purslane is common, not an uncommon weed and green. 
It is a type of Common Purslane, same Latin name you mention, Portulaca oleracea, that is a garden plant, a weed and a green here.
If I really wanted some purslane for salad, I would grow it in a pot.
I do grow some dandelions in the veg garden, which have longer leaves than local , wild dandelions.
