Curator Botany Leon Perrie was recently part of a panel that, for the first time, assessed the conservation status of all the mosses in Aotearoa New Zealand. Here, he introduces a few species you can report if you see them when you’re next mingling with moss.
There are about 500 species of mosses indigenous to New Zealand – roughly one-seventh of our native land plant biodiversity. Some species of moss, also known as pūkohukohu, are thriving, as they are common and widespread. This montage shows some of these common pūkohukohu.
Other species are not doing so well, or are poorly known. The Department of Conservation recently convened a panel to assess the conservation status of all mosses in New Zealand. The panel applied data such as herbarium specimens in collections like those of Te Papa, scientific publications, iNaturalist observations, and personal experience to the criteria of the New Zealand Threat Classification System.
The results showed 36 moss taxa (species, subspecies, or varieties) were assessed as Threatened and 156 as At Risk. A further 36 taxa were Data Deficient. Find out about the panel findings and classification system:
How you can help
Some of these species have not been seen for decades. Some are very small and can only be identified using a microscope.
Others, however, are more obvious and might be under-reported rather than genuinely rare. Some such examples are introduced below.
If you think you see any of these species, please upload photos to iNaturalist.nz. To be useful, the photos will need to include close-ups similar to the ones below. You will be helping future panels make more accurate assessments, which in turn keeps the conservation focus on the species that most need help.
Have you seen this moss?
Poo mosses, Tayloria
The wind is the primary means of dispersal for the spores of most mosses. But poo mosses have sticky spores and use smells to attract flies, which are then likely to disperse the spores to the preferred substrates of these mosses: dung and other decaying animal matter.
Each of the three resident species of Tayloria were assessed as At Risk – Uncommon. Poo mosses can be recognised by their broad leaves, stems with reddish hairs, and upright spore capsules, as well as their habit of growing on dung or animal remains.
Find out more about the Tayloria species:
- Flora of New Zealand treatment for Tayloria
- iNaturalist observations of Tayloria from New Zealand
- fuligogirl journal post about Tayloria octoblepharum
Fissidens dealbatus
One of the so-called pocket mosses of Fissidens. The leaves are flattened into one plane, and each leaf has a ‘pocket’ at its base on the side facing the stem apex. The pocket often partially encloses the base of the leaf in front.
Fissidens dealbatus was assessed as At Risk – Uncommon. Fissidens dealbatus is distinguished from other pocket mosses by its leaves lacking a vein through their middle, while having a border of elongated cells around their margins.
Look out for its silvery green patches on banks under forest, with each shoot less than 1 cm long. There are several recent observations from Wellington, indicating it can be present even within urban remnants of forest.
Find out more about the Fissidens dealbatus:
- Flora of New Zealand treatment for Fissidens dealbatus
- iNaturalist observations of Fissidens dealbatus from New Zealand
Fissidens berteroi
Another pocket moss, Fissidens berteroi, was assessed as Threatened – Nationally Vulnerable. It is aquatic and is usually on rocks submerged in flowing but stable creeks, such as those originating from springs.
There are several aquatic species of Fissidens, including the very common F. rigidulus, which has a distinctive blackish colouring and rather rigid shoots. However, a large, greenish Fissidens with leaves of 5 mm or longer and whose shoots are semi-floating in the water flow is likely F. berteroi.
Find out more about Fissidens berteroi:
- Flora of New Zealand treatment for Fissidens berteroi
- iNaturalist observations of Fissidens berteroi from New Zealand
Ptychomnion densifolium
The related Ptychomnion aciculare is so common that it is one of the few New Zealand mosses with a colloquial name – be it in English or Te Reo Māori. Pipe-cleaner moss is apt, and it is pictured in the montage above. It is likely to be found in all but the dryest forests.
On the other hand, Ptychomnion densifolium was assessed as At Risk – Uncommon. Unlike its forest-dwelling relative, P. densifolium occurs mostly above the treeline. Look out for it in subalpine or alpine grasslands and shrublands.
Ptychomnion densifolium is distinguished by its more densely-set leaves whose bases sheath the stem, meaning there is less of the stem visible than for P. aciculare. The Flora of New Zealand gives additional technical differences.
Find out more about Ptychomnion densifolium:
- Flora of New Zealand treatment for Ptychomnion densifolium
- iNaturalist observations of Ptychomnion densifolium in New Zealand
Beeveria distichophylloides
This species belongs to a group of mosses whose flattened form means they are often confused with liverworts. However, a close look will reveal a vein in the middle of their leaves, which liverworts never have.
From its relatives Achrophyllum and Distichophyllum, Beeveria distichophylloides is distinguished by some of its shoots ending in a ball of asexual propagules held out on a leafless stalk. That is utterly distinctive.
Assessed as At Risk – Uncommon, Beeveria distichophylloides is found on wet, base-rich rocks, particularly limestone, often in dense shade.
Beeveria distichophylloides is only found in New Zealand. It is the only species in the genus Beeveria, which is named for Jessica Beever by Allan Fife – they are the only two professional moss taxonomists in New Zealand in recent decades.
Find out more about Beeveria distichophylloide:
- Flora of New Zealand treatment for Beeveria distichophylloides
- iNaturalist observations of Beeveria distichophylloides
Cryphaea ovalifolia
Cryphaea mosses are distinctive for their spore capsules sitting immersed in leaf-like bracts. They are usually slender, somewhat wiry mosses that grow on twigs and small branches in sunny places such as forest margins.
Cryphaea ovalifolia differs by its broader leaf tips (not narrowly pointed), and it seems to be more robust than the common species. It was assessed as Data Deficient.
Find out more about Cryphaea ovalifolia:
Buxbaumia
Buxbaumia are unusual mosses in that they make few leaves. It is unclear how they derive their energy. Fortunately, from the perspective of recognising them, their spore capsules are rather distinctive: they are somewhat boat-shaped or egg-shaped with a conical apex and on stalks up to about 2.5 cm tall.
Both species in New Zealand were assessed as At Risk – Uncommon.
Find out more about Buxbaumia aphylla:
- Flora of New Zealand treatment for Buxbaumia
- iNaturalist observations of Buxbaumia in New Zealand
- fuligogirl journal post about Buxbaumia aphylla
Hylocomium splendens
In New Zealand, this species is confidently recorded only from the Raukūmara Ranges to the Tararua Ranges in the North Island. The Flora of New Zealand describes it occurring in high elevation “wind-swept” locations, although it can also be in beech forest. It was assessed as At Risk – Uncommon.
Several mosses have a similarly yellowish, branching habit. But plants with red stems in cold habitats could be Hylocomium splendens. There are unconfirmed reports from the South Island.
Find out more about Hylocomium splendens:
- Flora of New Zealand treatment for Hylocomium splendens
- iNaturalist observations of Hylocomium splendens in New Zealand
I love how this post shines a light on species we don’t often think about. The Giant moss growing tall enough to resemble pine seedlings is such an interesting characteristic. I’ll definitely pay more attention to mosses next time I’m out in nature!