elephant ear vine

Argyreia nervosa
Vine
Alternate
Simple
Pink
Green

A perennial woody vine growing up to 9 m. Leaves are heart-shaped (ovate-cordate, acute), glabrous (hairless) above and persistently white-tomentose (silver, hairy) underneath. Leaves are quite distinctive and can be more than 30 cm across. Flower colour varies from pale pink/white to dark pink/violet, generally with a much darker centre. Flowers are 5 cm in diameter. The pod is a dry capsule, c. 2 cm diameter, surrounded by a calyx that is divided into five sections. The structure has been likened to a carved rose (hence the Hawaiian common name of ‘woodrose’). Each pod contains 4–6 seeds.

Common names 
Also known as: baby woodrose, elephant climber, elephant creeper, elephant ear vine, elephant vine, Hawaiian baby woodrose, silver morning glory, wood rose, woolly morning glory,
Family 
Convolvulaceae
Deciduous 
No
Flowering time 
Spring and Summer
Native/Exotic 
Exotic
Origin 
India
Notifiable 
No
State declaration 
Category 3 - Must not be distributed or disposed. This means it must not be released into the environment unless the distribution or disposal is authorised in a regulation or under a permit.
Council declaration 
As per State Declaration
Known distribution 

This species is scattered across a large area of coastal northern and central Queensland. Specimens have been recorded at numerous locations within these regions, including around Townsville (i.e. at Mount Elliot and in the Townsville Town Common), on the Cape York Peninsula, and in the Cooktown, Ingham, Bowen and Calliope areas. It is particularly abundant around the Peter Faust Dam near Bowen.

Habitat 

This species is a weed of tropical and sub-tropical habitats, including rainforests, open woodlands, roadsides, distrubed sites and waste areas.

Habit 

A robust climber that grow up to a height of 10 m or more and can cover trees.

Impact and control methods 

Elephant creeper (Argyreia nervosa) is regarded as an environmental weed in northern Queensland and is included on the Cape York Peninsula priority weed list. It is an aggressive invader of rainforest and other tropical forest communities in northern Queensland and has been observed to smother trees, much like rubber vine (Cryptostegia grandiflora). Anecdotal reports from Queensland National Parks and Wildlife staff suggests that it can germinate quite readily in seemingly undisturbed sites, and it is capable of growing under rainforest canopies and among dense grass cover in eucalypt woodlands.
It thrives around Townsville, which has a comparatively low rainfall and is in a dry monsoonal area, and is also aggressive around Cooktown, where the summer rainfall is very high. Hence, elephant creeper (Argyreia nervosa) is seen as a potential threat to conservation areas in both the wet tropics and dry tropics regions.

Stem and leaves 

Its stems are relatively thick and become woody with age. The younger stems are densely covered in whitish coloured hairs.
The large leaves (15-30 cm long and 13-30 cm wide) are heart-shaped (i.e. ovate-cordate) with pointed tips (i.e. acute apices). They have hairless (i.e. glabrous) upper surfaces and persistently silvery-white hairy (i.e. tomentose) undersides. These leaves are alternately arranged along the stems and are borne on long stalks (i.e. petioles).

Flowers and fruits 

The large tubular flowers (5-7.5 cm long and about 5 cm across) are borne in clusters on long stalks (up to 15 cm long) that are covered in white hairs (i.e. on tomentose peduncles). They have five sepals (13-20 mm long when in flower) that are velvety-hairy like the undersides of the leaves. The petals are fused together into a tube (i.e. corolla tube) that varies in colour from pale pinkish to white with a much darker throat that is dark pink to violet. Flowering occurs mainly during spring and summer.
The fruit is a rounded (i.e. globose) leathery berry (1-2 cm across) that does not split open when mature (i.e. it is indehiscent). It is surrounded by the five persistent sepals and this structure has been likened to a carved rose (hence the Hawaiian common name of 'woodrose'). Each of these fruit contains 4-6 large seeds that are light or dark brown in colour.

Reproduction and dispersal 

This species reproduces mainly by seed, but it is also known to reproduce by vegetative fragmentation.
It seeds have been widely transported across the world for use as a garden ornamental and as a source of hallucinogenic drugs, and therefore seeds and plant parts may be spread in dumped garden waste. However, seeds are mainly thought to be dispersed into natural areas by fruit-eating (i.e. frugivorous) birds and other animals. Seeds and plant parts may also be dispersed in floodwaters.

Similar species 

Elephant creeper (Argyreia nervosa) is similar to several of the morning glories (i.e. Ipomoea spp.), including bush morning glory (Ipomoea carnea subsp. fistulosa), the native palmate-leaved morning glory (Ipomoea mauritiana), coastal morning glory (Ipomoea cairica), the native water spinach (Ipomoea aquatica) and sweet potato (Ipomoea batatas). These species all have large pale pinkish or purplish flowers with darker centres.