Macfadenya unguis-cacti.
Family Bignoniaceae.
The Cat’s claw creeper has also been in the genera Dolichandra and Bignonia.
It was introduced as a garden plant but is now an invasive weed in Queensland.
It is a rapidly growing, woody vine climbing by tendrils.
Undisturbed it can cover trees up to 30 m high and have stems 15 cm thick.
If there are no vertical supports it forms thick mats on the ground.
Adventitious roots form on both vertical and horizontal stems.
Tubers on the underground roots can be up 50 cm long.
The reddish new growth is hairy. Older stems are green then brown and woody.
In seedlings the leaves are simple and have a few small teeth.
Vines showing only horizontal growth may also have simple leaves.
Dark green, opposite, adult leaves are bifoliate with a tendril.
They are on petioles up to 2.5 cm long and the leaflet stalks are up to 7 mm.
Leaflets, up to around 7 cm long, are elliptic with a smooth, wavy margin and pointed tip.
The leaflet bases have dark glands on the underside.
The tendrils have 3 claw-like branches each up to 17 mm long.
The tips are very sharp and can hold onto the slightest roughness or indentation.
Older leaves on already attached stems may loose the tendril.
Inflorescences, a solitary flower or small cluster, are in the leaf axils.
The bright yellow flowers are up to10 cm long and 5 cm across.
The cup-shaped calyx, 1 or 2 cm long, has a wide rim.
It persists on the fruit.
The trumpet-shaped corolla has 5 rounded lobes 1 to 2 cm long, in 2 lips.
The 2 lobes in the upper lip are roughly vertical.
The three in the lower lip are almost horizontal.
The lower lip has 2 ridges and some faint red lines.
There are 2 pairs of stamens, one pair about 3 cm long, the other about 2 cm.
Stamens have hairy bases and there is a sterile staminode under 1 cm long.
The ovary has a style up to 3 cm long with a bilobed stigma.
The fruit are flat, dehiscent green then brown capsules up to 95 cm long and 12 mm wide.
They can hold over 100 flat brown seeds with 2 papery wings.
Seed and wings are up to 4 cm across.
Two varieties are described depending on the length of the capsules.
In S. E. Queensland the long-pod vines have larger leaves, deeper yellow
flowers and longer capsules.
J.F.
