Lauraceae the Laurel family.
The classification, number of species and genera in Lauraceae is uncertain at present.
The Plant List recognises 68 genera with another 47 uncertain.
Species can be difficult to identify and more are being discovered all the time.
They are found worldwide and the best known include the bay laurel tree, cinnamon,
camphor laurel and the avocado.
Many contain essential oils which are used for spices and perfumes.
Almost all are evergreen trees and shrubs and a few vines.
Leaves are mostly alternately arranged in spirals; rarely opposite or whorled.
The leathery leaves, on short stalks are usually simple but a few are lobed or dissected.
They are pinnately veined and cross-venulate, are gland-dotted and some have pits or hairs.
The small flowers, usually in clusters but occasionally solitary, are typically axillary.
They are typically bisexual but some species have both uni- and bi-sexual flowers on the one tree
and others have male and female flowers on separate plants.
There may or may not be bracts and the flower stalk may be swollen.
Some have distinct petals and sepals while others are undifferentiated tepals.
Typically there are 2 whorls of 3 (1 or 3 whorls occasionally).
Tepals may or may not be fleshy and are yellow, cream, white or green.
They are inserted on a hypantheum (a tubular or cup-shaped structure formed by the fusion of the lower
parts of the sepals, petals and stamens that commonly surrounds the carpels).
The hypantheum may only be present after fertilisation.
Stamens are mostly in 3 whorls of 3 but sometimes the inner ones are infertile (staminodes).
The filaments (stamen stalks) can be thin or flattened and petal like and can have small nectar
producing glands at their bases.
The filaments are fixed to the base of the anthers which open, usually inwards, via longitudinal valves or pores.
The ovary consists of 1 carpel with 1 style, 1 to 3 stigmas and 1 ovule.
The ovule develops into a seed enclosed by the hypantheum which can be fleshy or occasionally woody.
J.F.
