Four modern taxa representing the Araucariaceae, Cephalotaxaceae, Pinaceae, and Podocarpaceae were analyzed by the exhaustive search option with the Majonicaceae, using Ernestiodendron and Moyliostrobus together as the outgroup.
Florin (1951) and Schweitzer (1963) thought that the Cephalotaxaceae evolved from ancestors more like Ernestiodendron than Utrechtia (formerly Lebachia), because the ovuliferous scale in Cephalotaxus seems to consist of fertile elements only.
The Cephalotaxaceae appears as a sister group with the Araucariaceae in the tree summarizing the immunological studies of Price and Lowenstein (1989), which did not include the Taxaceae, and it is a sister group with the Podocarpaceae in my 1988 study.
My 1988 study links the Podocarpaceae and Cephalotaxaceae, but there is no agreement with other work, including the present results.
Other studies that include Hirmeriella place the latter at the base of a group that includes the Pinaceae and Araucariaceae (Miller, 1982: [ILLUSTRATION FOR FIGURE 4 OMITTED]), at the base of a group including all modern families except the Cephalotaxaceae (Miller, 1982: [ILLUSTRATION FOR FIGURE 3 OMITTED]), and at the base of a subclade involving the Cephalotaxaceae and the Podocarpaceae.
Hart's (1987) preliminary cladistic analysis supports this theory and positions the Cephalotaxaceae and the Taxaceae as sister groups.
Amentotaxus has been allied with Cephalotaxus as a member of the Cephalotaxaceae, the sister family and best outgroup to the Taxaceae (Hart, 1987; Keng, 1969).
The microsporangia are dorsiventral, but occasionally radial symmetry is displayed, at least near the strobilus apex, a condition also observed in the Cephalotaxaceae (Wilde, 1975).
Foliar resin is present in the leaves and arils as in Torreya and the Cephalotaxaceae, although Amentotaxus is the only genus of the Taxaceae that has its resin organized into a duct or canal (Ferguson, 1978; Jeffrey, 1903; Keng, 1969; Singh, 1961).