New Species of Wirerush Found in Northern New Zealand

Posted on July 9, 2012

Scientists have found a new species of wirerush in the wetlands in northern New Zealand. The northern part of the North Island of New Zealand is marked at approximately 38 degree S latitude by an ecological boundary known as the "kauri line". This region forms the southern distributional limit of many plants and it is the warmest part of New Zealand. A number of endemic plants are found there. Ecologists have recently discovered the new species of wirerush in peatlands north of the kauri line.

The peat-forming wetlands are dominated by a plant commonly known as wirerush (Empodisma, Restionaceae). The name Empodisma is derived from a Greek word meaning "to hinder."

The horizontal root systems of wirerush branch profusely forming finely divided rootlets with long-lived root hairs. In wirerush bogs, the underlying peat is formed largely from the remains of the root systems, stems bases and trapped plant litter.

Steve Wagstaff and Beverly Clarkson say there are three species of wirerush, including the newly described species Empodisma robustum. Beverly Clarkson is pictured assessing the ecological condition of an Empodisma robustum wetland in the photograph above. Empodisma robustum is only found in peatlands in northern New Zealand, whereas E. minus is found in central and southern New Zealand and eastern Australia, and E. gracillimum is restricted to western Australia.

The image below shows the morphological characteristics of Empodisma robustum.

A) Vegetative shoot with attached leaves and flowers
B) Rhizomes with emerging vegetative shoots
C) Vegetative shoot with attached pistillate flower
D) Pistillate flower with attached bracts
E) Gynoecium
F) Mature nut
G) Vegetative shoot with attached staminate spikelet
H) Staminate flower with attached bracts
I) Staminate flower.

The research was published here in PhytoKeys.

PLANTS