ARTICLE : 2001 EVENING MEETING REPORTS

 Monday 19 February 2001: Taxonomy of Parahebe – Speaker: Phil Garnock-Jones

Parahebe is a small genus of subshrubs related to Hebe and Heliohebe.   It is found in New Zealand and New Guinea (recent work shows the Australian, P. lithophila, actually belongs in Derwentia).   Phil’s revision of Parahebe is one of the objectives of the Hebe programme based at Te Papa and is funded by the Public Good Science Fund.

Phil discussed the taxonomic problems in Parahebe at two levels.   First he introduced us to modern ideas about classification of species into higher level taxa such as genera and families.   Biologists now insist that all members of such groups must have their nearest relatives also classified in the same group.   This simple requirement poses some problems for Veronica and Parahebe because Hebe and other genera have evolved within them.   Possible alternative classifications were discussed, such as putting all the New Zealand Hebe and related genera back into Veronica, or enlarging Hebe to include all its New Zealand relatives.   Phil showed that there are no unique characters that define Parahebe – it is made up of the species that are left over when distinctive genera such as Hebe, Chionohebe and Heliohebe are recognised within the New Zealand Hebe complex.

Secondly, Phil stressed the importance of testing explicit hypotheses at species level.   He described how the process of speciation is rarely observed, but can be inferred by seeking evidence that refutes a “hypothesis of conspecificity” which is a fancy term for a species identification.   Any kind of evidence will do – morphology, genetics, or behaviour – so long as it compels us to reject the conspecificity hypothesis.   This is consistent with Popper’s definition of science, whereas seeking evidence to support the idea that a collection might be a new species is not.   Phil discussed the 18 species he will be recognising in Parahebe, following these criteria.   In particular, Phil proposes to divide the Parahebe catarractae complex as treated in Allan’s Flora, into five species.   To finish the talk, he showed slides of intergeneric hybrids between cushion-forming Chionohebe species and Parahebe trifida, P. birleyi, and a new species related to them.

 Monday 18 June 2001: Recent work on the evolution of the concept of scenic reserves in NZ – Speaker: Dr Geoff Park, writer and ecologist

Geoff, who learnt a lot about plants and landscapes from Tony Druce, wrote “Nga Uruora – The Groves of Life: Ecology and History in a NZ Landscape”.   The book is part ecology, part history, part personal odyssey, and offers a fresh perspective on our landscapes and our relationships with them.

Geoff’s talk brought together for the first time some of his essays which have appeared in various publications, e.g. Landscape.

In the early 1900s, the Public Works Act enabled land to be taken for scenery preservation purposes.   At that time, NZ was being created as a productive “southern Britain”.   Thus Te Reinga Falls Scenic Reserve was set aside in the early 1900s to protect the falls, NOT the bush in which they were situated.   The reserve was established to save a beautiful feature for tourists.   Typically, scenic reserves are small, and surrounded by quite different vegetation, e.g. pasture.

Percy Smith, who had been Surveyor-General, set about rescuing areas and protecting them, but he was not an ecologist, so he did not establish corridors between them.   He led the scenery preservationists who were government servants, and became Commissioner of Scenery Preservation in his retirement.   The result of this work was the core of the present Scenic Reserves.   The 1903 Scenery Preservation Act arose out of his concern at the loss of vegetation on the ever-changing landscape caused by rapid land clearance.

The Main Trunk Railway was a prime reason for setting up scenic reserves, because it was a route used by tourists.   For more information, contact Dr Geoff Park, ph 04 384 6679.

Chris Horne

 Monday 15 October 2001:   Sophora (Fabaceae) in NZ: taxonomy, distribution and biogeography Speaker: Peter Heenan, Curator of Herbarium, Landcare Research, Christchurch

Peter described his taxonomic treatment of the Sophora microphylla complex in NZ.
• Sophora microphylla sens. str. is endemic to NZ, and includes those plants with a distinct divaricating and/or strongly flexuose juvenile phase, orange-brown to yellow-brown juvenile stems, and distant leaflets.
• S. chathamica is reinstated at species rank
• S. fulvida is a new combination for the taxon previously known as S. microphylla var. fulvida
• S. godleyi is a new species
• S. molloyi is a new species

Only S. microphylla has a divaricating and / or strongly flexuose juvenile phase.   The other four are each distinguished by a number of leaf characters, e.g. S. fulvida and S. godleyi have distinctive leaf hairs.

S. chathamica is a predominantly coastal species in Northland, Auckland, Waikato, Wellington and the Chatham Islands.

S. fulvida occurs north of Auckland on volcanic rock outcrops.

S. godleyi occurs on calcareous mudstone and sandstone in eastern Taranaki, King Country, Wanganui and Manawatu.

S. molloyi is restricted to extremely dry and exposed bluffs and rock outcrops of southern North Island headlands, Kapiti Island and several islands in Cook Strait.

Peter described cluster analyses of 11 leaf and four growth habit characters which provide additional support for the revised classification.   He also discussed his key to Sophora in NZ, the occurrence of hybridism, the conservation status of each species, and biogeographical considerations.

Ed: the above is based on the abstract of the paper “Sophora (Fabaceae) in New Zealand: taxonomy, distribution, and biogeography” in NZ Journal of Botany, 2001, Vol 39: 17-53.