Locus classicus

Long before I became friends with Graeme Atkins, I was familiar with his role in the rediscovery of one of our native irises (Libertia) in the wild.

Finding a species not seen in the wild for decades (and presumed extinct) is the kind of thing that most botanists never achieve in their lifetime. However, as our friendship developed, I realised that this might struggle to even make the top five of the countless contributions that Graeme has made towards conservation and botany in this country (especially in his region of Tairāwhiti).

Whilst staying with Graeme in the spring of 2016 (as part of a trip to see Clianthus maximus and other interesting species in the wild), he showed me the clump of L. cranwelliae that had grown from the original piece that he collected at the time of rediscovering it (for the purposes of verifying its identity).

Given the isolated nature of the small wild population (c. 30 plants) that Graeme found, and the shifting nature of access to such places, it struck me that the Atkins family’s letterbox had morphed into a de facto locus classicus for Libertia cranwelliae.

Now I am well aware of what qualifies as the type locality for a species within botany, but in the context of L. cranwelliae, the unassuming setting of a letterbox and post-and-wire fence on a Tairāwhiti roadside is more central to its story than a small paragraph within botanical texts.

It reminds us that people are central to maintaining awareness of threatened species and ecosystems, as well as bringing to mind the conversation that would have revolved around that small patch of garden (and its tenant) ten years prior to my trip. It is also worth considering the role that horticulture and gardens have played within botany and conservation in NZ – as in the case of Pseudowintera insperata, which was recognised as being distinct on the basis of cultivated specimens at Auckland University’s grounds.

The final image here shows another aspect of how I developed a better understanding of this critically-endangered Libertia. As we were walking out from visiting the largest extant population of ngutu-kaka (Clianthus maximus), Graeme drew my attention towards this dry bank, which (unlike all the other dry banks we walked past over several days) was particularly similar in terms of aspect, slope and soil composition to the distant habitat in which he rediscovered L. cranwelliae.