I'm not at all familiar with this plant, so I really can't help in
this instance. My first instinct is to suggest it may indeed be a
member of the Acanthaceae on account of the pronounced bracts, but
then the tubular, saccate flowers are very typical of members of the
Bignoniaceae. The leaves and their distribution along the stems
suggest Caprifoliaceae so its a bit of a mystery. I'll pass the pic
on to an acquaintance in Portugal and see if he can throw any light on
its identity.