Conifers are the largest, most widespread, and most economically important group of gymnosperms (nonflowering seed plants), including about 630 species divided into six or seven families. Conifers are the oldest extant group of seed plants, dating back to more than 280 million years in the fossil record. Some of the current families and genera have long fossil records; for example, remarkably well-preserved and modern-appearing cones of the genus Araucaria dating to 160 million years ago have been discovered, and a well-preserved fossil pine cone dating to 130 million years ago can be compared directly with cones of living pine trees.

Conifer Diversity

All conifers are woody plants, mostly trees or sometimes shrubs. Typical conifers such as members of the pine, cypress, and araucaria families are recognized by their woody seed cones, with flattened or shield-shape cone scales arranged spirally or in pairs or whorls around a central axis. The woody-coned conifers usually...