Potamogeton tricarinatus

Floating pondweed

An interesting aquatic plant with fine, thin submerged leaves and thick floating emergent leaves. The stems can be up to 4m in length from where they root in the substrate. This species is found throughout Australia and is highly variable.

Potamogeton crispus

Curled pondweed

A very hardy cold tolerant and low light tolerant fully aquatic plant. They are fast growing with crinkly leaves. Pondweeds produce turions from which they can rapidly grow from - with whole fields seemingly appearing out of nowhere when water conditions are adequate.

Najas tenuifolia

Water nymph

A fast growing, fully aquatic plant that can live free-floating or rooted. It's an important source of cover for many species like shrimp and rainbowfish, and Naiad species are popular in the aquarium trade as 'fry-mops' (for spawning eggs and rearing baby fish).

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Hydrilla verticillata

Waterthyme

A cosmopolitan macrophyte that normally forms a mat just below the water surface. It is very similar to the introduced Elodea species in both looks and behaviour, though is slightly smaller and slower growing.

Utricularia aurea

Golden bladderwort

This is a carnivorous plant! The little black bladder traps on the leaves have little hairs, which when brushed against, a trapdoor opens and closes in milliseconds to suck in small aquatic animals.

Eriocaulon willdenovianum

Long-leaf pipewort

This plant is only found in very far north regions of Australia. Like most Eriocaulon, they grow in swamps and wetlands, prefering soft and low pH water. This is a partial underwater form, which resembles a small, spiky bush when fully submerged.

Blyxa aubertii

Roundfruit blyxa

A grass-like annual aquatic plant that generally grows in rosette form. It likes warm water with high nutrient substrates.

Vallisneria caulescens

Branching Val

A northern Australian species with bright red leaves in shallow water. While young plants look like typical Vallisneria species: strap-leaved eelgrasses that spread outwards along runners, mature plants develop branching stems that rise vertically from the rosette.

Aponogeton elongatus

Queensland Lace Plant

A tuberous aquatic plant that can live in seasonal streams, losing all its leaves and laying dormant through the dry period. They grow delicate leaves up to 30cm long and can also develop floating leaves, usually as a result of a stressor like crowding or turbid water.

Ottelia ovalifolia

Swamp lily

A rosette plant with floating leaves on long stalks. They have two types of flower - one is a white three petaled flower that emerges during the warmer months of the year, the other a self-pollinating flower that stays underwater.

Characeae sp.

Stonewort

While it looks like a true aquatic plant, this is actually a multicellular green algae. They have no roots and either float around or are wedged loosely in sediment or around structure.

Monochoria vaginalis

Heartshape false pickerelweed

An aquatic, but more commonly emergent macrophyte that is in the Pontederiaceae family, the water hyacinths. This plant however doesn't float but anchors into the substrate. It has small purple flowers.

Eleocharis sphacelata

Tall spikerush

While always almost emergent, this sedge can grow submerged in deep water under high light. Submerged leaves are softer and thinner than the rigid and hollow emergent leaves. They grow out via a thick woody rhizome.

Marsilea crenata

Scalloped Leaf Nardoo

A specialised aquatic fern which grows primarily in floodplains. Growing on a rhizome, this plant can have submerged hockey-stick shaped leaves, emergent four-leaf clover shaped leaves or floating larger four-leaf clover shaped leaves.

Elatine gratioloides

Waterwort

A high light plant. Waterwort is fast growing with very thin and delicate leaves which can be more prone to snail holes than other macrophytes.

Elatine gratioloides

Waterwort

The emergent form of elatine is very short and prostrate, quite different to the submerged form.

Pistia stratiotes

Water lettuce

A floating rosette plant that can rapidly utilise nitrogen in the water to grow quickly. While considered invasive in many areas, it is actually a native cosmopolitian tropical species. It simply becomes a nuisance in areas with nutrient pollution associated with human habitation.

Salvinia molesta

Giant salvinia

An invasive aquatic fern from South America. These plants stay afloat by using stiff hairs on their leaves to repel water and hold air. Biological controls such as the Salvinia weevil, Cyrtobagous salviniae, have been introduced to aid in controlling the weed.

Eichhornia crassipes

Common water hyacinth

Also originally from Amazonia, water hyacinth is now considered one of the world's worst weeds. They have swollen, hollow leaf bases that are used to stay afloat. It is a very fast grower, and produces ramets (clones) readily via runners.

Ceratophyllum demersum

Hornwort

An interesting free-floating aquatic plant that does not form roots. It has allelopathic properties, excreting a substance that inhibits the growth of cyanobacteria and phytoplankton.

Leptodictyum riparium

Stringy moss

A cosmopolitian riparian moss species that can grow submerged. The only continent is is not found in is Antarctica. It's a messy grower, sprawling in every direction and can form thick soft mats over substrate.

Riccia fluitans

Floating crystalwort

Another cosmopolitian species, this moss-like plant is actually a liverwort. Relatively uncommon in Australia, they like slow moving waters where they grow in shallow water and along banks. When dislodged, the clump floats to the surface.

Limnophila brownii

Brown's ambulia

This is the submerged form of this plant, with fine, fluffy looking leaf pinnae. The emergent form has solid leaves and can easily be mistaken for a different plant. They are fast growers.

Myriophyllum aquaticum

Parrot's feather

An invasive water milfoil species from Brazil. They can form dense mats along water banks and spread easily via stem fragments.

Myriophyllum aquaticum

Parrot's feather

Unlike many other Myriophyllum species, the emergent leaves of this plant remain feathery and fluffy looking. The emergent leaves also have a thick waxy cuticle that repels water, which helps to keep the flowering portion out of water.

Myriophyllum verrucosum

Red Water-milfoil

The underwater form of this milfoil is far larger than the emergent form which is prostate and stunted. Under high light these plants turn red or brown.

Ceratopteris thalictroides

Water sprite

An aquatic fern that if found primarily in still or stagnant waters. It is a fast grower with delicate underwater fronds, and can grow both rooted or free-floating.

Ceratopteris thalictroides

Water sprite

The emergent form looks quite different, with much thinner and tougher pinna. New plantlets often form from asexual buds on the fronds. These ferns are also tolerant of growing in brackish water.

Nymphaea nouchali

Day water lily

A water lily that grows throughout much of the Old World tropics. Flowers open during the day with pointed petals of white, pink or purple shades. They prefer slow moving or still waters, and need a high level of organic nutrients for their roots to feed on.

Nymphoides indica

Water snowflake

A lilypad-like plant that isn't even closely related to true water lilys! The name of the genus reflects this ('Nymphoides' meaning 'like Nymphaea'). The most obvious way to differentiate between them from a distance is the far smaller flower.

Nelumbo nucifera

Sacred lotus

A plant with a long history of cultivation, with all parts being edible. The leaves first grow on the water surface, but are held above the water line as the plant matures. The seeds are incredibly viable, and can germinate after over a thousand years of dormancy.

Ludwigia peploides

Floating primrose-willow

A native species with a cosmopolitan distribution. They can form fast-growing, floating mats, with shoots that spread out across the water. It can also grow emergent as a short herb with longer, pointier leaves.

Ludwigia perennis

Perennial water-primrose

Found in wetlands across northern Australia, this Ludwigia species has smaller flowers than most of the others in its genus. It grows to be a leggy shrub as a riparian plant or a creeping plant with delicate stems underwater.

Ludwigia longifolia

Long-leaf primrose-willow

An introduced species of ludwigia native to South America. It prefers to grow emersed, and can reach up to 3m growing along waterways. Species in the Ludwigia genus almost always have 4-petaled, yellow flowers.

Hygrophila angustifolia

Willow hygrophila

Often confused with Hygrophila salicifolia or corymbosa, this plant gets long narrow leaves underwater. They like high light and leaves often turn red in high iron, low nitrate waters.

Isachne confusa

Squat swamp millet

An interesting grass that can grow entirely underwater, yet not in a scraggly, leggy manner like some other aquatic grasses. This is the terrestrial form of the species, with a prostrate, squat growth habit. They grow along sandstone escarpment creeks and small sandy streams where the pH is quite low. Underwater however, they form a loose round bush of upright stems.

Isachne confusa

Squat swamp millet

This is the underwater form, looking perhaps a little bamboo-like with a sturdy hard stem and small leaves. The leaves are also very sturdy, almost plasticky, with a bright purple underside. This purple underside is not always present however, and is likely either a result of species variation or the nutrient ratios in the water.

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