The term 'TREE TAMARACK' is a combination of two different types of trees. The first tree, 'TREE, ' is a general term for a woody perennial plant that typically has a single stem or trunk and grows to a considerable height. The second tree, 'TAMARACK, ' is a species of coniferous tree native to North America and parts of Europe. It is also known as the Eastern LARCH, which is the solution to the crossword clue with five letters.