Lauraceae

The flowering plant family Lauraceae, the laurels, includes the true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genera any are aromatic evergreen trees or shrubs, but some, such as Sassafras, are deciduous, or include both deciduous and evergreen trees and shrubs, especially in tropical and temperate climates. The genus Cassytha is unique in the Lauraceae in that its members are parasitic vines.

Overview
The family has a worldwide distribution in tropical and warm climates. The Lauraceae are important components of tropical forests ranging from low-lying to montane. In several forested regions, Lauraceae are among the top five families in terms of the number of species present.

The Lauraceae give their name to habitats known as laurel forests, which have many trees that superficially resemble the Lauraceae, though they may belong to other plant families such as Magnoliaceae or Myrtaceae. Laurel forests of various types occur on most continents and on many major islands.

Although the taxonomy of the Lauraceae is still not settled, conservative estimates suggest some 52 genera worldwide, including 3,000 to 3,500 species. Compared to other plant families, the taxonomy of Lauraceae still is poorly understood. This is partly due to its great diversity, the difficulty of identifying the species, and partly because of inadequate investment in taxonomic work.

Recent monographs on small and medium-sized genera of Lauraceae (up to about 100 species) have revealed many new species. Similar increases in the numbers of species recognised in other larger genera are to be expected.

Description
Most of the Lauraceae are evergreen trees in habit. Exceptions include some two dozen species of Cassytha, all of which are obligately parasitic vines.The fruits of Lauraceae are drupes, one-seeded fleshy fruit with a hard layer, the endocarp, surrounding the seed. However, the endocarp is very thin, so the fruit resemble a one-seeded berry. The fruit in some species (particularly in the genera Ocotea and Oreodaphne) are partly immersed or covered in a cup-shaped or deep thick cupule, which is formed from the tube of the calyx where the peduncle joins the fruit; this gives the fruit an appearance similar to an acorn. In some Lindera species, the fruit have a hypocarpium at the base of the fruit.