The key includes 439 species and 4 hybrid taxa of indigenous and naturalised grasses of New Zealand.
| NZGrass Key | No. |
| Endemic species | 160 |
| Indigenous species | 30 |
| Naturalised (incl. transients) species | 248 |
| Hybrid taxa (all naturalised) | 4 |
| Total no. species & hybrid taxa | 442 |
This is less than the total number of 460 species recorded in Flora of New Zealand Volume 5 Gramineae (Edgar & Connor 2000). Thirty-five of the 45 species listed as transients in the flora have been left out as they have been recorded just once or twice in early times of European colonisation and not recorded since or, for a few cases of more recent records, it is unlikely that these species have established or persisted.
The key uses data contained in the descriptions of the Flora of New Zealand Volume 5 to produce a new key to all grass species in New Zealand. New data have been added for species in genera that were missing values for numeric ranges – Chionochloa, and Rytidosperma. The key also incorporates, for many species, extensions in ranges of quantitative characters from new incoming specimens into the Allan Herbarium.
Statistics
Grasses are the second largest plant family in New Zealand with 464 species (190 indigenous species and 274 naturalised species (Edgar & Connor 2010) making up 11% of seed plants in New Zealand (indigenous & naturalised). Endemism is high with 84% of species found nowhere else. The grasses have the largest number of naturalised species of any plant family, exceeding the number indigenous grass species by 12%, and making up 7% of all seed plants in New Zealand. Grasslands and mosaics of grass and scrub cover nearly 60% of New Zealand (Wardle 1991).
Most indigenous grasses are concentrated in three tribes – the Agrostideae (Agrostis, Lachnagrostis, Deschampsia, Deyeuxia, Koeleria, Trisetum), Danthonieae (Chionochloa, Rytidosperma), and the Poeae (Festuca, Poa). The panicoids are poorly represented with just three indigenous species, and bamboos are absent altogether.
Naturalised species are concentrated in the Agrostideae (Agrostis, Anthoxanthum, Avena, Phalaris), Hordeeae (Critesion), Paniceae (Panicum, Paspalum, Pennisetum, Setaria) and the Poeae (Festuca, Poa). About 40% of naturalised species are from Europe and 15% are from Australia. Most of the European species belong to the genera Avena, Critesion, Poa or Festuca. Nearly all the naturalised Australian species are from the stipoid genus Austrostipa or the danthoid genus Rytidosperma. Another stipoid genus present here is Nassella from South America, represented by three weedy species, including the well-known invasive ‘nassella tussock’ (Nassella trichotoma).
Sources of information
Champion P, James T, Popay I, Ford K 2012. An Illustrated Guide to Common Grasses, Sedges and Rushes of New Zealand. New Zealand Plant Protection Society.
Edgar E, Connor HE 2000. Flora of New Zealand Volume 5 Gramineae. Lincoln, New Zealand, Manaaki Whenua Press.
Edgar E, Connor HE 2010. Flora of New Zealand Volume 5 Gramineae. 2nd Edition. Lincoln, New Zealand, Manaaki Whenua Press.
Sharp D, Simon BK 2002. AusGrass (Grasses of Australia). Australian Biological Resources Study, Canberra (ABRS), CSIRO Publishing.
Wardle P 1991. Vegetation of New Zealand. Chapter 9 Grassland and herbfield. Cambridge, Cambridge University Press.
Acknowledgements
The TFBIS (Terrestial & Freshwater Biodiversity Information System) Programme fully funded this project.
The authors of Flora of New Zealand Volume 5 Gramineae, Elizabeth Edgar and Henry Connor, gave their permission to use the flora descriptions as the basis for this key and to link to the digitised version of the flora.
Mary Barkworth from the University of Utah (Editor for Gramineae for the Flora of North America Project) provided high-resolution images of line drawings covering nearly all of New Zealand’s naturalised flora.
Graeme Bourdot (AgResearch), Rowan Buxton, Graeme Jane, Peter Johnson, Carolyn Lusk (AgResearch), Chris Morse (Manaaki Whenua – Landcare Research), Colin Ogle, Jeremy Rolfe, Alice Shanks, Geoff Walls and Hilary Webb (Horizons Regional Council) provided photographs and plant specimens. Rowan Buxton, Chris Morse, Mike Thorsen (Dept of Conservation) and Susan Wiser (Landcare Research) gave helpful comments to improve the key and alerted us to errors.
The publisher of the Grass Flora, Manaaki Whenua Press, gave permission to reproduce illustrations by Pat Brooke, Sabrina Malcolm, Peter Johnson and Keith West.
Donovan Sharp and Bryan Simon (authors of AusGrass: Grasses of Australia) and ABRS (Australian Biological Resources Study) allowed us to use their character glossary images. Bryan Simon also encouraged us to change from a generic key to a species key.
