The Soapberry or Maple family.
There are around 140 genera (135 – 150) and 1900 (1325 – 2000) species.
Australia has around 190 species in 30 genera.
Subfamilies, with some better known genera include:
- Dodonaeoideae with Dodonaea and Harpullia,
- Hippocastanoideae with Acer,
- Hippocastaneae with Aesculus (chestnut),
- Sapindoideae with Cardiospermum.
Of uncertain placement are Alectryon, Cupaniopsis, Diploglottis, Jagera, Koelreuteria, Lepiderema, Litchi and Sapindus.
They are trees, shrubs, herbs, scramblers or climbers using tendrils that are modified inflorescences.
Many produce a milky latex.
The leaves are mostly alternate and in a spiral but are sometimes opposite.
The petiole often has a swollen base of specialised vascular tissue that allows movement.
Only a few have stipules.
Some have juvenile leaves that differ from the adult ones.
Most have compound leaves that can be trifoliate, pinnate or bipinnate.
Leaflet petiolules usually have a pulvinus and the terminal leaflet may be reduced to a small spur.
In those with simple leaves they are often dissected.
There are often glands and domatia (small tufts of hair or pits).
Terminal or axillary inflorescences are mostly along, or on the ends of large branches in the crown.
They are rarely a solitary flower being mostly a variously arranged, branched cluster.
Most of the usually small flowers are on a stalk or pedicel.
There are bracts and often bracteoles.
Flowers may be bisexual, or unisexual with each on the same or different plants.
There is usually a hypogynous disc as a gland, disc or indistinct patch.
Some have the stamens &/or ovary on a stalk.
There are 4 or 5 (3 -7) sepals that may be free or joined at the base.
The corolla has 4 or 5 (0) petals that are usually joined.
Petals often have a claw base.
They often have 1 or 2 hairy, scale-like basal appendages on the inner surface.
There are mostly 4 – 5 or 8- 10 (6 – many) stamens in 1 or 2 whorls.
They are typically inserted inside the nectiferous disc.
There are often hairs (appendages) on the filaments.
The dorsi or basi-fixed anthers open inwards via longitudinal slits.
In male flowers the stamens, all fertile, extend beyond the corolla.
In female flowers the stamens are reduced or resemble sepals.
The superior ovary, from 3 (2, 6, 8) united carpels, has 1 to 8 locules.
There is usually a single (2 – 4) style with 2 or 3 stigma lobes.
The 1 (2) ovules in each locule have basal or axile placentation.
In male flowers the ovary is rudimentary.
The fleshy or dry fruit can be nuts, berries, drupes, schizocarps, samaras or a capsule that opens in various ways.
The seeds frequently have an aril (a fleshy thickening where the seed is attached).