The Genus Pinus

A systematic, comparative survey of pines that analyzes external and internal morphology—seedlings, leaves, buds, conelets, cones, seeds, wood and bark—and evaluates these characters for delimiting species. The study traces an evolutionary sequence of cone and seed structure from relatively primitive conditions to highly specialized and sometimes serotinous cones, using those trends to organize a sectional classification. Detailed treatments cover cone color and dimensions, peduncle articulation, umbo position and apophysis form, phyllotaxis, cone tissues and seed anatomy, and wood and bark structure, followed by an arranged key of sections, subsections and species groups based on the morphological evidence.