Peter J. de Lange

19 posts
A former Department of Conservation scientist, Peter has been visiting the Chatham Islands since 1996. He is currently Associate Professor at Unitec in Auckland and is a current member of the Chatham Islands Conservation Board.
Rust on Mangere

A new highly threatened enigmatic rust recognised from Chatham Islands forget-me-not

During January 2007 the Auckland Botanical Society visited the Chatham Islands. During their visit the late Dr Ross Beever, then a mycologist working for Landcare Research discovered a strange, orange rust growing on cultivated plants of Chatham Islands forget-me-not (Myosotidium hortensia) within the visitor car park gardens, Department of Conservation offices, Te One, Chatham Islands

Sonchus grandifolius just starting to flower Te Henga. Image: Peter J. de Lange

Sow thistle gets a name revival and a little rusty

Last year the Chatham Islands lost one of its unique genera. The endemic Chatham Islands sow thistle was originally described by New Zealand botanist Thomas Kirk (1828–1898) as a new species of Sonchus, S. grandifolius (Kirk 1894). Then in 1965 botanist Loufty Boulos transferred S. grandifolius and the Australian endemic S. megalocarpus to a new genus Embergeria (Eichler 1965). Later Nicholas Lander (Lander 1976) transferred the Australian Embergeria megalocarpus to another new endemic Australian genus Actites leaving the Chatham Islands E. grandifolius the sole representative of the genus Embergeria, which by default was now a Chatham Islands endemic.

Chatham Island linen flax

New Plant Threat Listing Includes Chatham’s Species

The May 2012 threat assessment of the New Zealand Indigenous Vascular Plant flora is now published (see de Lange et al. 2013). The list which covers the entire indigenous vascular plant flora, including that of the Chatham Islands and 166 informally recognised, ‘tag name’ entities is now available at http://www.doc.govt.nz/upload/documents/science-and-technical/nztcs3entire.pdf  […]

1. Lepidium oleraceum – Cook’s Scurvy Grass is of course not a grass but a large shrubby cress with a flavour not unlike watercress.

Remarkable and unexpected diversity of scurvy grasses discovered on the Chatham Islands

The New Zealand scurvy grasses (Lepidium species) include the famous Cook’s scurvy grass (L. oleraceum), a species which has gained almost legendary status as the plant that saved Captain Cook and his crew from the depredations of scurvy. Whilst modern research has shown that this is gross exaggeration it cannot be doubted that this plant and its allies were important green foods for not only scurvy ridden sailors but iwi (who in New Zealand knew the plants collectively as ‘nau’).

Chatham Island toetoe

Study reveals low levels of genetic diversity in Chatham Islands toetoe

A study just published in Pacific Conservation Biology reveals that the Chatham Island toetoe (Austroderiaturbaria) populations have very little significant genetic variation (Houliston et al. 2012). The discovery comes as somewhat of a worrying surprise to plant conservationists. Previously, without the ability to check levels of genetic variation the Department […]