Craspedia Research At the Allan Herbarium, Landcare Research, Lincoln: Progress ReportCraspedia (Asteraceae: Gnaphalieae) is a genus of 23 species found only in Australia and New Zealand. Its species have confusing and continuous character variation and indistinct boundaries, which makes their relationships difficult to elucidate.
The New Zealand species of Craspedia have long been regarded as one of New Zealand’s most difficult and important taxonomic group of higher plants. I started to revise the genus in 1996, but soon realised that with my increasing leadership role at Landcare Research, it would be almost impossible to undertake this revision. A revision of Craspedia requires full time research of about 6 years. Staff at the Allan Herbarium agreed that I would work on Craspedia as a very long term research project.
So, what have we achieved so far?
First of all, I wanted to test whether Craspedia in New Zealand is monophyletic. Phylogenetic analyses of ITS, ETS and psbA-trnH non-coding spacers showed that New Zealand Craspedia is derived from a single dispersal event over the Tasman Sea from south-east Australia. Therefore we can exclude conspecifity with Australian species and can delimit the revision of Craspedia to the New Zealand species.
We (Kerry Ford, Jo Ward, Rob Smissen, Steve Wagstaff and Ilse Breitwieser) have now almost completed our manuscript that is based on Kerry Ford’s MSc thesis on “Origin and Biogeography of New Zealand Craspedia (Compositae: Gnaphalieae)”.
Rob Smissen, Kerry Ford and I are currently using molecular methods to gain more insight into what is a species in Craspedia. We are looking at uniform entities, such as an unnamed Craspedia believed endemic to Kaitorete Spit in Canterbury, also at areas where different looking entities occur sympatrically (e.g., three sympatric entities at Mt Arthur, Kahurangi National Park) and finally at areas where there appears to be obvious hybridisation between several entities (e.g., between Island Saddle and No Man’s Creek in Marlborough).
For the revision, many helpers and I collected specimens of all of Tony Druce’s tag name entities and of the described taxa. We are growing about 300 plants in one of Landcare Research’s glasshouses under uniform conditions. I have measured them for a wide range of characters (e.g., corolla colour, pollen colour, anther tube colour, corolla length, floret number of capitulum, floret number of glomerule, glomerule diameter and shape, scape length / width, scape colour, several rosette leaf characters, several characters of leaf hairs, fruit set). Kerry Ford has measured and scored fruits from all of Tony Druce’s tag name entities and has undertaken a preliminary analysis. Numerous helpers, particularly Department of Conservation staff and keen amateurs, are sending us specimens. Over the years we have collected many specimens and scored their characters. I have also started measuring leaf characters from other herbarium specimens. All herbarium specimens are databased. A lot of time will still be needed to score herbarium specimens and to analyse data.
So, what are the more short term plans?
1) Submit manuscript on origin and biogeography of Craspedia.
2) Write a manuscript on first results from the genetic research.
3) Write a manuscript on the fruit data.
I would like to thank all those who have contributed specimens to the Craspedia study. Each specimen is very valuable and will be included in the research. I hope to continue to provide updates on the revision as and when new results arise.