Could be "split poles" or if you want it more specific "half round
". Sometimes they say "half pole" (in case you have already mentioned that bamboo, or the reader somehow knows that beforehand).
Also "split bamboo poles" (assuming that is half pole, with a picture for example
There is "bamboo" cooking parlance, so "peixe (nome do peixe) assado na taquara" would be "fish (name the fish) cooked in bamboo" OR sometimes "chiken bamboo" (for example). So, no need to explain that it is cooked in a half cut section of a bamboo pole, one would assume that.
Since, most the time it´s cooked in said half pole, albeit sometimes it´s used a section cut from a pole, and it´s not a half, but in something like a small tube.
Carpa assada na taquara.http://www.sbs.com.au/food/recipes/whol ... -nuong-tre
Sometimes they use bamboo bamboo sticks in cooking.
It´s worth noticing that not all bamboos are equal, chances are that one find some poisonous some day, so adventurers sometimes use a kit to test for some known poisonous substances.