The order includes about 2500–2800 species from 85 to 90 genera, which comprise seven families oftrees andshrubs. 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 theLauraceae (for examplebay laurel,cinnamon,avocado, andSassafras), and the ornamental shrubCalycanthus of the Calycanthaceae.
The earliest lauraceousfossils are from the earlyCretaceous. It is possible that the ancient origin of this order is one of the reasons for its highly diverged morphology. Presently no single morphological property is known, which would unify all the members of Laurales. The presently accepted classification is based on molecular and genetic analysis.
The first botanist to think of the Laurales as a natural group was H. Hallier in 1905. He viewed them as being derived from theMagnoliales. During some or all of the 20th century, the Laurales generally includedAmborella and the plants now classified inAustrobaileyales andChloranthaceae. They were not removed until the advent of molecular data in the late 20th century; their previous inclusion made it harder to determine the relationships within the Laurales and between the Laurales and other groups.[3]
^Angiosperm Phylogeny Group (2003). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II".Botanical Journal of the Linnean Society.141 (4):399–436.doi:10.1046/j.1095-8339.2003.t01-1-00158.x.
Endress, P.K.; Igersheim, A. (1997). "Gynoecium diversity and systematics of the Laurales".Botanical Journal of the Linnean Society.125 (2):93–168.doi:10.1006/bojl.1997.0113.
