- douglas fir - strong durable timber of a douglas fir
--1 is a kind of fir
--1 is a substance of douglas fir- douglas fir - tall evergreen timber tree of western North America having resinous wood and short needles
--2 is a kind of conifer, coniferous tree
--2 is a member of Pseudotsuga, genus Pseudotsuga
--2 has substance: douglas fir
--2 has particulars:green douglas fir, douglas spruce, douglas pine, douglas hemlock, Oregon fir, Oregon pine, Pseudotsuga menziesii; big-cone spruce, big-cone douglas fir, Pseudotsuga macrocarpa - douglas fir - tall evergreen timber tree of western North America having resinous wood and short needles