In the next two weeks, some of Te Papa’s Botany staff will be looking for several poorly known mosses and liverworts.

For instance, the moss Dicranoweisia spenceri was recorded more than 60 years ago from near Mount Ruapehu but it hasn’t been reported from there since – is it still there? We’re going to check.

Conservation managers need to know what is rare and what is not. It allows them to prioritise (increasingly) stretched resources to those plants and animals at most risk of extinction.

New Zealand’s herbaria (collections of dried plant specimens) collectively have over one million specimens (Te Papa has c. 250000). These collections voucher, or provide physical proof, of what plants are in New Zealand, what they look like, and where they occur. Many species occur commonly and over large areas, but many others are only known from a few sites, placing them at risk of extinction.

Te Papa’s botany collection.

New Zealand Virtual Herbarium – an aggregate database of NZ’s herbaria.

One million specimens sounds a lot. But there’s still huge gaps in the documentation of New Zealand’s native plants (not to mention adventive and cultivated plants).

Mosses and liverworts pose a particular challenge. They’re small and underappreciated, and there’s far fewer people capable of identifying them compared with bigger plants.

What are mosses and liverworts?

There are about 520 mosses and 600 liverwort species in New Zealand. Yet in the recent threat evaluation of these groups, 135 taxa/entities are listed as “Data Deficient”. That is, not enough is known about them to even rate how threatened they are.

The 2010 evaluation of the threat status for New Zealand’s mosses and liverworts.

Which is why the Bryophyte and Lichen Workshop is so important. This is an annual gathering of people – amateurs and professionals, beginners and experts – interested in mosses, liverworts, and lichens. This year the Workshop is based in Matawai, between Opotiki and Gisborne. Three staff and a Research Associate from Te Papa are taking part. There’s very few previous records of mosses and liverworts from the Matawai area, so we’ll be collecting a specimen of every species we find, including common species. But we’ll have a close eye out for those regarded as Data Deficient, both during the Workshop and at targeted sites during our travel there and back.

I’ll let you know what we turn up.