|Laurus nobilis flowers and leaves|
The order includes about 2500-2800 species from 85-90 genera, which comprise seven families of trees and shrubs. Most of the species are tropical and subtropical, though a few genera reach the temperate zone. The best known species in this order are those of the Lauraceae (for example bay laurel or Laurus, cinnamon or Cinnamomum, avocado or Persea, and Sassafras), and the spice bush or Calycanthus of the Calycanthaceae.
The earliest lauraceous fossils are from to the early Cretaceous[source?] It is possible that the ancient origin of this order is one of the reasons for its highly diverged morphology. Indeed, presently no single morphological property is known, which would unify all the members of Laurales. This fact used to cause much argument among botanists regarding the correct circumscription of the order, and the presently accepted classification is based on recent molecular and genetic analysis.