Creeping Burrhead

Echinodorus cordifolius syn E. radicans
Aquatic
Basal
Simple
White
Green

This long-lived water plant forms clumps of upright leaves that emerge up to 1m above the water surface. These clumps are usually connected to each other by spreading underwater stems that are rooted to the soil or creek bottom. 

Common names 
Also known as: Creeping Burrhead, Radican sword, Long leaf amazon sword,
Family 
Alismataceae
Deciduous 
No
Flowering time 
late summer and early autumn
Native/Exotic 
Exotic
Origin 
South Eastern USA to South America
Notifiable 
No
State declaration 
Nil
Council declaration 
NIL - Reduce
Known distribution 

In recent years this species has become naturalised in a few waterways in the Brisbane and Gold Coast areas in south-eastern Queensland. The first confirmed record was in March 2004, from a drainage line in Lawnton in the northern suburbs of Brisbane. Creeping burrhead has since been recorded along Breakfast Creek in Newmarket, in Coombabah Lake Conservation Park (about 3
km from Helensvale) and along a creek in Mackenzie

Habitat 

It is usually found growing in swamps, wet woodlands, marshes, and ditches. There are some indications that it prefers a slightly shaded location. Most rapid growth is generally on wetland soils with fairly high organic matter. 

Habit 

They are slender plants that are seldom more than 30 cm tall. They can live completely submerged under water and have rhizomes and adventitious shoots that facilitate asexual reproduction. 

Impact and control methods 
Stem and leaves 

The leaves are borne on very long stalks (17.5-45cm long) that are ridged. They are somewhat spade-shaped or narrowly oval (6.5-30cm long and 2.5-20cm wide) with entire margins and 3-5 distinct veins running lengthwise.

Flowers and fruits 

The very long flowering stems (up to 1.5m long) are arching in nature or spread outwards across the water surface. There are several clusters of 3-15 flowers arranged at widely separated intervals along each of these slender stems. The white flowers are up to 25mm across when fully open and are borne on long stalks (2-7.5cm long). Each flower has three small greenish sepals and three broad white petals. They also have about 20 small yellow stamens in the centre. Several small fruit (2-3.5mm long) are produced by each flower. These fruit are 3-4 ribbed and have a short beak at the tip. Flowering usually occurs during late summer and early autumn.

Reproduction and dispersal 

Clumps or segments of the underwater stems can separate from each other and form new colonies after being spread downstream during floods. However, plants are most often spread by the deliberate dumping of unwanted plants into waterways.

Similar species 

Creeping burrhead is very similar to Sagittaria (Sagittaria platyphylla), another introduced water weed. However, Sagittaria leaves only have a single prominent central vein. It also has relatively thick upright flowering stems with flowers always arranged in threes.