Aristolochiaceae.
There are 10 to 12 genera and around 480 (300 to 500) species.
There are nearly 500 synonyms.
Asutralia has 8 or 10 species including 4 in S. E. Queensland.
A number of species are similar in appearance.
Some are shrubs or rarely herbs but most are woody vines.
The simple or lobed, alternate leaves are on petioles.
There are no true stipules but some species have a leaf-like pseudostipule.
The pseudostipule is the first leaf of an undeveloped axillary shoot.
Axillary inflorescences are single flowers or small clusters.
They are bisexual and often have a foul smell to attract pollinators.
Flowers may have rudimentary petals but most have none.
The enlarged calyx is coloured and resembles a petal.
The straight or curved, tubular base expands into 1 to 3 large lobes.
The basal part encloses the reproductive organs.
There are 6 to many stamens on short, thick filaments, in 1 or 2 whorls.
They may lie free around the ovary or be fused to the style.
The anthers may be free or attached to the style or the 3 or 6 stigmatic lobes.
Anthers open outwards via longitudinal slits.
The mostly inferior ovary has 4 to 6, usually fused carpels and 4 to 6 locules.
There are numerous ovules in each locule.
The fruit are septicidal capsules mostly with 6 chambers.
The flat seeds occasionally have wings.
J.F.
