Through the range of Agathis there is considerable variation in characters of the living tree. Height may reach 45-60 m and girth 6 m, but some kinds of Agathis probably never reach such huge dimensions.The bole (Plate 1) may be cylindrical or may .taper (though never strongly) and sometimes has markedly spiral grain. Sometimes there is a tap root, and several big 'sinker' or 'peg' roots may develop. Buttresses do not form, but big swollen superficial roots sometimes occur, and sometimes the butt is swollen to a varying degree. The bark (Plates 4, 5) is scaly, the scales being roundish, sometimes compoundly so as to resemble pieces of a jigsaw puzzle.