Last week, Antony and I joined Greater Wellington Regional Council staff, Robyn Smith and Tim Park, to check out a few plants that are uncommon locally.
The highlight was seeing Tim’s recent discovery of a new population of the button daisy Leptinella maniototo, near Porirua. This is only the second known North Island population, the other being at Lake Wairarapa (where it is now possibly extinct). It is otherwise known from the central and southern South Island. This is a very tiny plant, so Tim did well to spot it, and Robyn to identify it.
It is a surprise that the Porirua population has been overlooked until now, leading some to ask whether it is natural, or a naturalisation?
Beforehand we had stopped near Titahi Bay to locate the population of southern shore spleenwort (Asplenium obtusatum). This fern is abundant around parts of the South Island, but it is at its northern limit around Wellington, where it is quite patchy and uncommon. Robyn was interested in locating a healthy population to source spores from for propagation for restoration projects. My job was to verify the identification, because southern shore spleenwort looks very similar to shining spleenwort (A. oblongifolium). Southern shore spleenwort has broader scales on its stems, and its frond segments tend to have blunter ends. It can withstand much more exposed sites.
The Titahi Bay area is home to some magnificent coastal vegetation, albeit under threat from an assortment of weeds. We were pleased to also spot an individual of the uncommon Melicytus obovatus (or an undescribed ally thereof). It has much bigger leaves than M. crassifolius, with which it was growing and which is much more common locally. Both are coastal, shrubby relatives of the common forest tree mahoe (M. ramiflorus).