Hamamelidaceae



Hamamelidaceae – Witch Hazel family.

The Witch Hazel family has 26 to 29 genera and 80 to 100 species depending on the classification.
Most people seem to exclude the Altingiaceae and include the Disanthaceae.
Genera include Disanthus, Hamamelis, Loropetalum and the 3 found in Australia – Neostrearia,
    Noahdendron and Ostrearia.

Loropetalum and the three Australian genera are in the subfamily Hamamelidoideae.
This is the largest of the 5 or 6 subfamilies with 22 genera.

They are mostly trees and shrubs, evergreen or deciduous and usually have stellate hairs.
Leaves are mostly alternately arranged and in a spiral or 2 ranks.
They are on stalks and usually have stipules that may fall off early.
Stipules, usually in pairs, can be very small to a few quite large ones.
The leaf blade is simple or palmately lobed with (3) 5 – 7 lobes.
Venation is pinnate or palmate.

Plants are uni or bi-sexual or combinations of perfect and uni-sexual flowers.
Inflorescences are terminal or axillary.
They consist of small flowers often crowded onto a spike or into a head.
There are bracts at the base of the inflorescence stalk and often with the individual flowers.
A hypanthium may be present as may a hypogynous disc between the stamens and ovary.
(A hypanthium is a tubular structure with the calyx lobes and petals attached to the top.)

There is usually a distinct calyx and corolla but the whole perianth may look like sepals.

Rarely there is no perianth.

The calyx has 4 to 5 (7) sepals that are free or joined and is usually persistent.
Occasionally there is no calyx.
The corolla usually has 4 – 5 (0-10) small, ribbon-like petals that are free or partly joined.
They can be white, red, yellow or greenish.
Occasionally there is no corolla.

There are 4 -5 (10-32) stamens that are free of each other and in 1 or 2 whorls.
They alternate with the petals and some may be infertile staminodes.
The anthers are basifixed and dehisce via slits, pores or valves.
The connective tissue between the anther sacs is usually enlarged.

The ovary is usually inferior but occasionally superior.
There are usually 2 (3) carpels that are free, fused or fused just at the base.
There are 2 (3) apical, erect or curved styles that are free or partly joined.
Styles and stigmas are persistent.
The 2 – 3 locules have 1 – 6 (15) ovules, many of which may abort often leaving only one.

Fruit are woody, dehiscent capsules that break through the sutures or into the chamber.
The seeds may or may not have wings.

J.F.

Genus