Oleaceae
Mostly polygamo-monoecious or polygamo-dioecious trees or shrubs. Leaves simple or compound, opposite, rarely alternate. Flowers 4-merous, regular, usually bracteate, sessile or pedicellate. Calyx synsepalous, lobes obsolete or nearly so; corolla sympetalous or absent; stamens usually 2, with large anthers and short filaments; carpels 2, stigmas capitate, ovoid, or 2-cleft, style solitary, ovary superior, 2-locular, usually 4-ovulate. Fruit a drupe or samara, usually 1-seeded.
Leave pinnately compound; fruit a samara..............................................................................................Fraxinus
Leave simple; fruit a drupe or berry.
Corolla absent; leaves toothed..........................................................................................................Forestiera
Corolla present; leaves entire or denticulate.
Petals linear, united at base only; young inflorescence spreading or drooping.....................Chionanthus
Petals not linear, united into a distinct tube; young inflorescence erect.
Inflorescence a few-flowered axillary panicle........................................................................Osmanthus
Inflorescence a many-flowered terminal panicle.....................................................................Ligustrum
Leave pinnately compound; fruit a samara..............................................................................................Fraxinus
Leave simple; fruit a drupe or berry.
Corolla absent; leaves toothed..........................................................................................................Forestiera
Corolla present; leaves entire or denticulate.
Petals linear, united at base only; young inflorescence spreading or drooping.....................Chionanthus
Petals not linear, united into a distinct tube; young inflorescence erect.
Inflorescence a few-flowered axillary panicle........................................................................Osmanthus
Inflorescence a many-flowered terminal panicle.....................................................................Ligustrum