Vegetative and reproductive structures referred to the genus Rissikia from Australia and Africa are podocarpaceous, as are several Jurassic forms. Recently a podocarpaceous stem has been described from the Triassic of Antarctica. The Pinaceae are the best known and largest family of extant conifers, and are probably the most familiar to you because they are a predominantly northern hemisphere group well represented in the current flora. These plants are monecious trees with leaves that are spirally arranged, linear or needlelike. Pollen cones in this group have 2 microsporangia per microsporophyll while seed cones bear 2 ovules per woody cone scale, and have scales and bracts that are free from one another.
Pollen is bisaccate.
The fossil record of the Pinaceae extends from at least the Cretaceous based on anatomically preserved cones. However, a number of Triassic and Jurassic compressed fossils that are less completely known have also been suggested as members of the Pinaceae. In the Cretaceous, numerous pinaceous cones are found anatomically preserved. Although a few can be assigned to the modern genus Pinus , most are placed in the fossil genus Pityostrobus because they combine characters not found in modern taxa. Other modern pinaceous genera evolved during the Tertiary.