It is 16 steps long and shows Araucaria, Cephalotaxus, and Podocarpus branching from within the Majonicaceae but Pinus diverging basal to this family.
Both Cupressus and Taxodium show a single shortest tree of 19 steps when analyzed with group 2 taxa [ILLUSTRATION FOR FIGURES 16 & 18 OMITTED], and both are linked as sister taxa with Cephalotaxus in their trees (((((Cupressus or Taxodium, Cephalotaxus)((Dolmitia, Pseudovoltzia) Araucaria) Majonica, Podocarpus) Pinus) outgroup).
The ten remaining genera of ancient conifers representing the Cheirolepidiaceae, Ullmanniaceae, and Voltziaceae (Mapes & Rothwell, 1991; Miller, 1977) were analyzed first with group 1, consisting of the Majonicaceae, Taxodiaceae, Sciadopityaceae, and Cupressaceae, using Ernestiodendron as the outgroup, and then with group 2, consisting of the Majonicaceae plus Pinus, Araucaria, Podocarpus, and Cephalotaxus, using both Ernestiodendron and Moyliostrobus as the outgroup.
The strict consensus tree ((Aethophyllum, Pseudovoltzia, Dolmitia) Pinus, Podocarpus, Cephalotaxus, Majonica) outgroup) shows Aethophyllum on an unresolved trichotomy with Pseudovoltzia and Dolmitia.
The strict consensus ((((((Cycadocarpidium, Araucaria) Dolmitia, Pseudovoltzia) Cephalotaxus) Majonica, Podocarpus) Pinus) outgroup) shows it paired with Araucaria, and the two branch from an unresolved trichotomy with Dolmitia and Pseudovoltzia.
In the strict consensus tree (((((Dolmitia, Pseudovoltzia) Araucaria) Pararaucaria, Cephalotaxus, Podocarpus) Pinus) outgroup) Dolmitia and Pseudovoltzia are sister taxa.
The strict consensus tree (((((Dolmitia, Pseudovoltzia) Araucaria) Cephalotaxus, Podocarpus) Pinus) outgroup) shows Pinus on one branch of a basal dichotomy, with the rest of ingroup on the other branch.
This group shares a node with Araucaria, which in turn is linked with Cephalotaxus. This subclade branches from an unresolved trichotomy with Majonica and Podocarpus.
The pollen strobilus of Amentotaxus lacks bracts but otherwise strongly resembles the compound arrangement of the pollen strobilus of Cephalotaxus. 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).
It is distinguished from Cephalotaxus by its shorter, alternate leaves and open, red aril.
Torreya is distinguished from Cephalotaxus by its sessile or subsessile axils, lack of a prominent mid-rib, sunken stomatal bands that are narrower than or equal to the midrib and spine-tipped leaves.