pennywort

Centella asiatica
Aquatic
Basal
Simple
Pink
Purple
Green

A long-lived herbaceous plant with creeping stems that regularly produce roots at the joints. Its leaves are arranged in clusters along the stems and are borne on stalks 0.5-15 cm long. These leaves (1-4.5 cm long and 1.5-5 cm wide) are kidney-shaped and usually have bluntly toothed margins. Its inconspicuous pink or purplish flowers are arranged in small clusters. Its small fruit (2.2-5 mm wide) are ribbed and split into two one-seeded segments when mature.

Common names 
Also known as: Pennywort,
Family 
Apiaceae
Deciduous 
No
Flowering time 
Summer - Autumn
Native/Exotic 
Native
Origin 
Native to most parts of Asia and Oceania
Notifiable 
No
Council declaration 
SIL – Special Investigation List
Known distribution 

This species is widespread in the tropical, sub-tropical and warm-temperate regions of the world (i.e. it is almost cosmopolitan). Its exact origin is obscure, but it is thought to be native to the Indian sub-continent, south-eastern Asia and Australia. It is native to the coastal and sub-coastal districts of southern, eastern and northern Australia (i.e. south-western Western Australia, south-eastern South Australia, Victoria, eastern New South Wales, eastern Queensland, and the northern parts of the Northern Territory.Naturalised on Lord Howe Island and Norfolk Island.

Habitat 

Pennywort (Centella asiatica) is a very widespread native plant that is particularly common in wetlands and damp habitats in grasslands, open woodlands and pastures. It is also a minor weed of lawns, gardens and disturbed sites.

Habit 

A long-lived (i.e. perennial) herbaceous plant with creeping (i.e. prostrate) stems.

Impact and control methods 

Centella asiatica quickly exploits localised soil disturbance to establish in riparian zones.

Stem and leaves 

The stems are long creeping runners (i.e. stolons) that regularly produce roots at the joints (i.e. nodes). The leaves are arranged in clusters (i.e. rosettes) along the creeping stems and are borne on stalks (i.e. petioles) 0.5-15 cm long. The bases of these leaf stalks are broadened and sheath-like in nature. The leaf blades (1-4.5 cm long and 1.5-5 cm wide) are kidney-shaped (i.e. reniform), heart-shaped (i.e. cordate) or somewhat rounded in shape (i.e. sub-orbicular). They are hairless (i.e. glabrous) with bluntly toothed (i.e. crenate) margins.

Flowers and fruits 

The inconspicuous flowers are arranged in small clusters (i.e. umbels), with one to four of these clusters present in some of the leaf forks (i.e. axils). These clusters contain 2-4 flowers and are borne on stalks (i.e. peduncles) 2-15 mm long. The individual flowers are stalkless or almost so (i.e. sessile or sub-sessile) and are without sepals. These flowers have five small pink, purplish or whitish petals. They also have five deep purple stamens and an ovary topped with two styles. The bases of these styles are fused and swollen and there are small stigmas at their tips. The small fruit (2.2-5 mm wide and 2.1-3 mm high) have 7-9 ribs. These fruit split into two one-seeded segments (i.e. mericarps) when mature, each with 3-5 ribs.

Reproduction and dispersal 

This species spreads by seed and also vegetatively via its creeping stems (i.e. stolons).Its creeping stems spread laterally to form large colonies, while its seeds are probably spread by water and in contaminated soil.