Finding rare plants with GW

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.

Close up of Leptinella maniototo, with several flowering inflorescences, each c. 2 mm across. Its narrow leaves and leaf-segments, and its shortly-stalked inflorescences are distinctive. Photo © Leon Perrie.

The green is the Leptinella manitoto, thriving on the dry mud. The red is a species of Crassula. Photo © Tim Park.

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?

NZ Plant Conservation Network page on Leptinella maniototo.

Southern shore spleenwort, Asplenium obtusatum, Titahi Bay. Photo © Tim Park.

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.

Melicytus obovatus, Titahi Bay. Photo © Tim Park.

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).

 
 
 
 

2 Responses

  1. Leon Perrie

    Thanks Phil. Robyn and Tim are already on to that. I understand that the nearest bowling green is in Titahi Bay at that Robyn was going to check it out. Haven’t heard yet what she found.

    Reply
  2. Phil Garnock-Jones

    Leon
    It would be worth checking if L. maniototo is in any bowling greens nearby. Cotula greens are an ideal habitat for this species because its usual environment is in temporary moraine pools, and it propagates vegetatively by bulbils that take advantage of fluctuating water levels of flooded greens.

    Reply

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