Lauraceae

Lore & Background

The Lauraceae are an ancient lineage of flowering plants, with fossils common since the Cretaceous. Their present-day distribution reflects a combination of historical biogeography and later dispersal; although once interpreted as a classic Gondwanan pattern, subsequent work suggests some distribution patterns are more recent. The family includes both evergreen and deciduous trees, with the genus Cassytha being unique as parasitic vines. Many species contain high concentrations of essential oils, some valued for spices and perfumes, while others are highly toxic. The fruits are drupes, one-seeded fleshy fruits with a thin endocarp, resembling a berry; in some species the fruit is partly covered by a cupule formed from the calyx tube, giving an acorn-like appearance.

Reader's Guide

Lauraceae are significant as a major component of tropical forests worldwide, often ranking among the top five families in species number in forested regions. They give their name to laurel forests, habitats where many trees superficially resemble Lauraceae though they may belong to other families. The family has been economically important: Cinnamomum provides cinnamon and cassia; Camphora yields camphor; Laurus nobilis supplies bay leaves; and Persea americana produces avocados, oil-rich fruit cultivated globally. Many species are exploited for timber and medicinal materials. However, habitat loss and overexploitation have put many species in danger of extinction, while some, like Cinnamomum camphora, are invasive in regions such as South Africa. The taxonomy of Lauraceae remains poorly understood due to great diversity and inadequate investment in taxonomic work, with recent monographs revealing many new species.

Did You Know?

• The genus Cassytha is unique in the Lauraceae because its members are parasitic vines.
• Lauraceae flowers are protogynous, often with a complex flowering system to prevent inbreeding.
• Laurel wilt disease, caused by the fungal pathogen Raffaelea lauricola, was found in the southeast United States in 2002.
• Some Lauraceae species have adapted to swampy conditions by growing pneumatophores, roots that project above periodic flood levels.