KEY TO THE GENERA (based on sterile specimens)

1Leaves glandular-dotted beneath. Stipules peltately attached
1'Leaves not glandular-dotted. Stipules not peltate.
2Leaves in whorls of 3. Stipules interpetiolar
2'Leaves spiral. Stipules not interpetiolar.
3Leaves not crowded near the end of the twigs. Terminal buds not conferted, scales imbricate or rarely with a tendency to distichy.
3'Leaves crowded at the end of the branchlets. Terminal buds conferted, scales with a tendency to orthostichy
4Wood-rays (of older branches and mature wood) exclusively uniseriate.
4'Wood-rays uniseriate and many-celled