31. The sapwood of all timber species should be considered to be non-durable without preservative treatment. 32. Southern magnolia has yellowish-white sapwood and light to dark brown heartwood tinted yellow or green. 33. The bark hack is swung much like an axe and is used to create a hatched sapwood . 34. Occasionally it contains pale streaks of a similar colour to the sapwood , as in the picture. 35. The underlying sapwood , which has been killed and colonized by the pathogen, is rarely discolored. 36. The sapwood is light yellow, while the heartwood is chestnut brown with patches of dark violet. 37. Its wood is extremely heavy with intercrossed grains; the sapwood is white, and heartwood brown. 38. The wood is hard and heavy, with well-marked differences between sapwood and heartwood timber. 39. Young larvae chew their way along the grain of sapwood but older larvae may tunnel across the grain. 40. These toxins reduce the conductance of sapwood being built, which causes water stress and kills the trees.