MONOCOTYLEDONS

PONTEDERIACEAE

A small family of some 30 aquatic perennials, mostly tropical. There are four species in Western Australia, two native and two naturalised. Eichhornia crassipes (water hyacinth) DP is one of the world's worst water weeds. It forms a free-floating clump with upright, almost circular leaves with swollen, spongy stalks. Introduced from South America because of its beautiful, sky-blue flowers, it spreads rapidly by stolons and can grow from fragments, quickly covering open water. In 1947, dumped aquarium material spread to totally cover Lake Monger in Perth, prompting a successful eradication effort which has been maintained, although the plant still occasionally turns up in garden ponds. More recently, many of the freshwater lakes and swamps throughout the Perth region have been invaded. Pontederia cordata (pickerel weed) is a rhizomatous plant with heart-shaped leaves and dense spikes of violet-coloured flowers, spreading from plantings in an urban creek in Perth. Native to eastern North America.


Eichhornia crassipes , PH

POTAMOGETONACEAE -
Pondweed Family

A family of some 100 aquatic perennials, growing from rhizomes. The leaves can be submerged or floating. Nine species in Western Australia, one naturalised outside its normal range. Potamogeton crispus (curly pondweed) is a submerged perennial, with stems up to 1m long. The leaves are 2-6mm long with a narrowly ovate-oblong, obtuse blade, minutely toothed and undulate along the margin. The inflorescence is an emergent spike of 10 to 15 green flowers, in spring and summer. It is naturalised in Lake Monger but native to the Kimberley and tropical Australia. Differs from other local potamogetons in the submerged, undulate to crisped leaves.


Potamogeton crispus , AW

TECOPHILAEACEAE

A small family of perennials, mostly with corms, from South Africa and South America. One species naturalised in Western Australia. Cyanella hyacinthoides has a rosette of numerous bright green leaves that wither in early summer, just as the stiffly-branched stem to 30cm begins to produce its flowers. These are about 2cm across, pale violet-blue, with prominent yellow stamens. The plant dies back to a corm over summer. A garden escape, it is locally abundant in disturbed areas around Perth, York and Tammin. Native to South Africa.


Cyanella hyacinthoides , JD

TYPHACEAE - Bulrush Family

This worldwide family has only one genus, Typha (bulrush, cattail) and in Western Australia there are two species, one native and one naturalised. They are tall, stiffly-upright aquatic perennials, growing from a rhizome and flowering in early summer. The inflorescence is a dense spike, male flowers on top and female below. T. orientalis (bulrush, cumbungi) is native to eastern Australia but not to Western Australia and has a leaf blade up to 14mm wide. It is an aggressive coloniser of disturbed wetlands in the Swan Coastal Plain and elsewhere.


Typha orientalis , RR

T. domingensis (yanget) that is native to all Australian States, is a much more delicate plant. It has a leaf blade that does not exceed 8mm in width. Intermediates exist, and it is sometimes difficult to tell which species is being dealt with.


T. domingensis , GK
 

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