Heartwood samples of Pacific Coastal Douglas-fir (Pseudotsuga
menziesii var. menziesii) and Rocky Mountain Douglas-fir
(Pseudotsuga menziesii var. glauca) were rated for relative liquid
permeability, and evaluated for kraft pulping characteristics.
Highly impermeable wood of the Rocky Mountain variety was termed
"refractory," while the pervious wood of the Pacific Coastal variety...