Austroderia richardii, syn. Cortaderia richardii, is a species of flowering plant in the family Poaceae. It is an evergreen perennial grass. The genus Austroderia is often confused with "pampas grass", which usually refers to Cortaderia selloana. "Early pampas-grass" is a more specific name. The name "tussock grass" may also be found. The Maori name is "toetoe". It is one of five species commonly called toetoe in the genus Austroderia that are endemic to New Zealand. It occurs in the South Island and possibly also in the North Island. It is also an introduced species in Tasmania, Australia.
Description
A. richardii are large sized grasses that can grow to around 1.5 to 3 m tall. Its leaves are sharp-edged from 1 m long and around 2 to 5 cm wide. Because of its fine, sharp teeth along the edges of the leaves, it is often referred to as "cutty grass". Its leaves are coarse, green, flat and narrow with upright flowering culms 2.5 m tall (Kimberley, 2011). Culms are the hollow stem of the flowering grass plant. These high culms are the main identifying feature of the A. richardii as they have great arching, dense, silvery plumes at the top of the culms which makes them very elegant and stand out from other Austroderia (Kimberley, 2011). The flower head is usually one-sided and drooping. The flower head has many fine hanging branches which contain numerous small clusters of flowers encased in soft, hairy scales. The plumes appear to be a creamy buff to yellowish colour and grow to around 30–60 cm in length and have a loose/open appearance. This is what gives the A. richardii its distinctive thick, soft, plume-like look from its flowering heads. The leaves of the plant have multiple prominent veins running down either side of the middle of the leaf. This makes them a lot tougher and stronger compared to the introduced pampas grass which looks very similar but this is one way of identifying the difference.
A. richardii usually flower around spring and early summer (September to November) though they always retain their plumes. It implements a stage of fruiting around the October and March months. All Austroderia species in New Zealand, including introduced ones, have been proven to be gynodioecious. Being gynodioecious means they are involved in a dimorphic breeding system in which male-sterile individuals coexist with hermaphroditic individuals in populations. Hermaphrodites may be self-compatible also (Connor H. E, 1973). Hermaphrodite Austroderia can be characterized by their large pollen-filled anthers and small gynoecia (the female part of the flower). While female plants have flat, white or transparent, sterile anthers with larger gynoecia (Connor H. E, 1973). Both of these types of sex form seeds. Their seeds are wind dispersed.
Distribution and habitat
A. richardii is endemic to New Zealand but is an introduced species in Tasmania, Australia (Sharp, 2002). In New Zealand, it is confined to only the South Island but could possibly grow in the North Island, East of Cape Palliser (Edgar, 2000).
A. richardii is a very hardy and tolerant grass species that is able to adapt to a wide variety of habitats including, streamside, wetlands, scrubland and coastal sand dunes. It is most suited to moist or dry soils as well as sand so is able to grow effectively in the habitats mentioned. It can tolerate very poor soils such as sand on coastal dunes and is able to thrive in frost-prone regions. It is well suited to a coastal environment as it can withstand poor soil environments that the dunes appear to have as well as the coastal wind and precipitation effects that occur in coastal regions, for example on the west coast of the South Island or east coast.
A. richardii is suited to many different types of environmental conditions but prefers areas around water (Kimberley, 2011). This shows that the plant prefers to have a lot of moisture uptake. Although it is best suited to moist soil it can tolerate soils which are poor in nutrients such as those soils with the main component being sand, clay or pumice. These soils will lack nutrients due to having too little or too much moisture in them.