spiked pepper

Piper aduncum
comparison of spiked pepper (Piper aduncum), left, and Mexican leaf pepper (Piper auritum), right
Shrub
Alternate
Simple
White
Green

a multi-stemmed shrub or small tree growing up to 7 m tall.

its produces distinctive short stilt roots arising from the joints at the bases of its stems.

its younger branches have swollen, purplish coloured, joints.

its alternately arranged leaves give off a strong peppery odour.

its elongated, pale yellow or greenish, curved flower spikes (10-20 cm long) are produced in the upper leaf forks.

its small rounded fruit turn blackish in colour as they mature.

Common names 
Also known as: bamboo piper, cow's foot, false kava, false matico, jointwood, matico pepper, stilt root piper,
Family 
Piperaceae
Deciduous 
No
Flowering time 
Flowering and fruiting occurs throughout the year
Native/Exotic 
Exotic
Origin 
This species is native to southern Mexico, Central America, the Caribbean and tropical South America.
Notifiable 
Yes
State declaration 
Category 1
Council declaration 
As per State Declaration
Known distribution 

Naturalised on Christmas Island.

Habitat 

A potential weed of disturbed rainforest, forest margins, coastal environs, roadsides, waterways, plantations and pastures.

Habit 

A multi-stemmed shrub or small tree growing up to 7 m tall, usually with distinctive short stilt roots arising from the joints (i.e. nodes) near the base of its stems.

Spiked pepper (Piper aduncum) is a potential weed of disturbed rainforests, forest margins, coastal environs, roadsides, waterways, plantations and pastures in the tropical regions of Australia. This species is a serious environmental weed in other parts of the world and is expected to be invasive in the humid coastal regions of northern Australia. It is listed in the Global Invasive Species Database and in on the Northern Australia Quarantine Strategy (NAQS) list.

Stem and leaves 

The branches are held upright (i.e. erect), but have drooping twigs towards their extremities. These younger branches are hairless (i.e. glabrous) and have swollen, purplish coloured, joints (i.e. nodes). Older trunks have smooth and grey or greenish coloured bark.

The alternately arranged leaves are simple and borne on short stalks (i.e. petioles). These leaves (12-22 cm long) are narrowly oval (i.e. elliptic) in shape with entire margins and pointed tips (i.e. acute apices). The upper leaf surfaces are lightly rough in texture (i.e. scabrid), while their undersides are softly hairy (i.e. pubescent). Leaves and younger stems give off a strong peppery odour (i.e. they are aromatic).

Flowers and fruits 

The elongated and curved flower clusters (10-20 cm long) are produced in the upper leaf forks (i.e. axils). These clusters (i.e spikes) are borne on a stalk (i.e. peduncle) that is 12-17 mm long. The tiny flowers are white to pale yellow in colour at first, but turn green as they mature, and are densely crowded in regular rows. Each flower usually has four stamens, but no obvious petals or sepals (i.e. the perianth is absent). Flowering and fruiting occurs throughout the year.

The rounded (i.e. globose) fruit is a small one-seeded berry that turns blackish in colour as it matures. The flattened (i.e. compressed) seeds are brown to black in colour (0.7-1.25 mm long), glossy in appearance, and have a finely networked (i.e. reticulate) surface texture.

Reproduction and dispersal 

This species reproduces by seeds and also occasionally by root suckers.

Most dispersal of the tiny seeds is by fruit-eating (i.e. frugivorous) birds, flying foxes and other animals, although it may be introduced into new areas by machinery and other vehicles. Plants may also spread locally via suckers, and can form quite large clumps.

Similar species 

Spiked pepper (Piper aduncum) is quite distinctive, and is rarely confused with other species. A native plant known as giant pepper vine (Piper novae-hollandiae) has similar leaves and flower clusters, but it can be very easily distinguished by its climbing habit.