Plastid DNA restriction site and rearrangement mutations were used to study phylogenetic relationships among hard pines (subgenus Pinus). Total genomic DNA was cut with 19 restriction enzymes, blotted, and then probed mostly with 80% of the Douglas-Fir (Pseudotsuga menziesii) chioroplast genome (cpDNA) {initial study, using only 6bp recognition enzymes}; or,...