The Richmond Birdwing butterfly vine is also known as Pararistolochia praevenosa.
It is native to the N.E. and S. E. coastal areas of Queensland.
Plants are the food for the larval stages of the Richmond Birdwing Butterfly.
They are a large perennial woody vine (liana) with older stems 3 to 4 cm across.
Long branched stems climb by twining or leaning on any support.
Most parts have few to dense brown hairs at least when young.
Alternately arranged leaves are in 2 ranks (distichous).
Their thick curved or twisted petiole can be up to around 3 cm long.
The elliptic to ovate blades can be over 20 cm long.
The base is rounded or sometimes heart-shaped (cordate).
There are brown hairs on the midrib and veins on the lower surface.
The prominent veins are pinnate with 5 to 10 roughly paired along the midrib.
Inflorescences, usually but not always in the leaf axils are racemes.
They are short with up to 5 or 6 stalked flowers along the midrib.
There are brown hairs on many parts.
Petals are absent but the white, purple and yellow sepals are petal-like.
Flowers are strongly bilaterally symmetric.
The calyx, 2 to 2.5 cm long has a tubular base with 3 short, slightly curled back lobes.
Attached to the top of the ovary the tube pouches out around the reproductive parts.
It then narrows to the throat then widens into the funnel-shaped upper section.
On the rim are 3 lobes with 1 in the upper lip and 2 in the lower.
The outer surface is a white to pale cream with purple veins.
Along the funnel are increasingly dense purple spots.
There are simple hairs mainly along the veins.
On the inner surface the pouch is purple with soft matted hairs.
The pale throat is smooth with no hairs.
The inner surface of the funnel is white with dense stout white downward pointing hairs.
The bright yellow inner surface of the lobes has no hairs.
There are wide purple veins running down the throat, funnel and lobes.
Male and female reproductive parts are fused to form a gynostegium.
The 6 short stamen filaments are fused to the base of the style forming a short column.
The 1 mm long anthers are fused to the outer surface of the stigmatic lobes.
The inferior ovary of 6 fused carpels has a ribbed outer surface with brown hairs.
Each of the 6 locules has numerous ovules in vertical rows.
The oblong indehiscent fleshy orange fruit, around 3 mm long are markedly ribbed.
Each chamber has numerous 4 mm long seeds.
J.F.
