Melastomataceae or Melastomaceae.
There are about 165 (163 – 182) genera and 5115 (4400 – 5600) species.
Genera include Centradenia, Heterocentron, Medinilla, Melastoma, Osbeckia and Tibouchina.
Recognising specimens as part of the family is easy but identification of the genera and
species can be very difficult.
They are commonly shrubs but also herbs, trees and lianas.
The stems are often 4-angled with ridges or wings.
Many parts have hairs of various types.
Leaves, on petioles, are largely opposite and decussate but may be whorled.
They may or may not have petioles.
Blades are ovate, lanceolate or oblong with smooth, toothed or slightly lobed edges.
There is typically no dominant midrib but 3 to 9 prominent and roughly parallel veins.
They arise at the base or along a mid-vein.
There are various types of hairs – simple, branched, stellate and with or without glands.
Hairs are sometimes feathered.
Terminal or axillary, bisexual flowers are usually in clusters but some are solitary.
Most have no nectaries with nectar produced from the perianth or stamens.
There are often bracteoles and these are often coloured.
There is a hypanthium that can be tubular or bell-shaped.
The calyx has 4 or 5 (3 – 10) sepals mostly incorporated into the hypanthium.
Their lobes, on the rim of the hypanthium, can be blunt or toothed or may be absent.
There are the same number of petals as sepals.
There are 4 to 5 (8, 10 or many) stamens, all fertile or with some staminodes.
They can be in 1 whorl or in 2 whorls.
The filaments are often twisted so all the anthers lie on one side of the flower.
In some genera the stamens are equal in length and of similar appearance.
In others half may be shorter with no, or very small, appendages from the anther connective tissue.
The basifixed or dorsifixed anthers may also have a small spur.
Anthers open via 1 (rarely 2 or 4) terminal pores or lateral slits.
The ovary can be superior (the hypanthium is free from it) to partly inferior (hypanthium adherent).
There are 4 or 5 fused carpels (2 – 15) in the ovary.
There are usually an equal number of locules but occasionally only one or two.
The usually axile placentas hold a few to many ovules.
The single style has a simple or lobed stigma with papillae.
The fruit are a loculicidal or septifragal capsule or a berry.
In a septifragal capsule the outer walls of the segments separate from the septa (partitions).
Each segment has 20 to 100 small seeds.
J.F.
