Division II. Dicotyledons.
Stems formed of bark, wood, or pith, and increasing by the addition of an annual layer of wood inside the bark. Parts of the flower mostly in 4’s and 5’s; embryo with a pair of opposite cotyledons. Leaves netted-veined.
Subdivision 1. Apetalæ. Flowers without a corolla and sometimes without a calyx (with a corolla in Olacaceæ).
Section 1. Flowers in unisexual aments (female flowers of Juglans and Quercus solitary or in spikes); ovary inferior (superior in Leitneriaceæ) when calyx is present.