Kia ora koutou,

I’ve decided to start a little project which I’m calling “the year of moss”. Every day, for 365 days, I will be making a little post about a species of moss found in Aotearoa. It might be a species I saw that day. It might be a species I saw a few days before. It might just be a random draw from the NZ moss flora. Each day, I’ll post a little bit of info about the species and what makes it interesting. For a bit of amusement, I’ll also give each species a “rating” on cuteness, distinctiveness, and overall “Liadan’s moss rating”, or LMR for short.

I’ll start us off with Leptostomum macrocarpum. This species is widespread around Aotearoa, occurring from the far north all the way down to Fiordland. It grows in damp forests, usually on the bark of trees. Despite being distinctive and widespread, I saw L. macrocarpum for the first time just last week at the John Child bryophytes workshop in Whangārei. I guess I spend too much time in the forests east of Arthur’s Pass, which are mostly too dry for this species. L. macrocarpum has several distinctive features that set it apart from any other mosses in Aotearoa, including a branched hairpoint on the leaves and a distinctive capsule shape. Its capsule shape is, I think, best described as an elongated potato. The capsules are lumpy things that are widest at the base and narrow a little towards the tip. When capsules are present, they usually occur in a dense weft, which is presumably how this species got its common name “pincushion moss”.
Cuteness: 8/10
Distinctiveness: 10/10
LMR: 8/10
Here’s an observation of this species from last week’s workshop: https://inaturalist.nz/observations/246881079

Today I decided I’d write about the first moss I found after walking out the door. This was it: Bryum argenteum. This species is all over the cities of Aotearoa, and all over most cities in the world, cropping up wherever a tiny bit of dirt accumulates on the pavement. This is truly an impressive species, found on every continent of the world, including Antarctica. Unlike other species in the genus Bryum, Bryum argenteum is distinctive and easily identified to species level. The tips of its leaves are unpigmented, which gives the entire plant a silvery sheen. At least, when it's not covered in the grime and dust associated with growing in a gutter on the side of the road. Although I wouldn’t call this species “cute”, its incredible hardiness to cold, heat, pollution, and exposure certainly boosts its LMR (“Liadan’s moss rating”).
Cuteness: 2/10
Distinctiveness: 10/10
LMR: 7/10

Yesterday’s moss got me wondering what other species Aotearoa shares with Antarctica. Antarctica has about 100 species of mosses, and there are actually quite a few of those that also occur here. One of those shared species is Ceratodon purpureus. C. purpureus is very common in roadside verges and other disturbed habitats, including naturally disturbed habitats such as riverbeds. This species has pigments that protect it from sun exposure in these open habitats, and its colour can vary from green to orange-y, depending on the level of these pigments. C. purpureus is fairly distinctive when sporophytes are present, as they have a distinctive red seta (that’s the ‘stem’ of the sporophyte), and capsule shape. However, when sporophytes are not present, you’ll probably need a microscope to recognise this species. Another moss that’s not very cute, but gets a few extra points for hardiness.
Cuteness: 3/10
Distinctiveness: 8/10
LMR: 7/10
See here for an old observation of mine of this species, featuring me slowly learning to ID mosses in the ID history :) https://inaturalist.nz/observations/91877717

I spent today out on Banks Peninsula climbing at Ōtepatotu. Ōtepatotu is a lovely crag, tucked into a little patch of forest, with both excellent rock climbing and excellent mosses (two things I love). I photographed quite a few different mosses while out there, but the one I’m sharing today is Lembophyllum divulsum. This species occurs in Aotearoa and Australia, and is most often seen in forest habitats, but can also grow in open grassland. The leaves of L. divulsum look like tiny round bowls, which stack together along the stem to produce a shingle-like texture. L. divulsum apparently has traditional Māori uses in hunting (as a bird-snare disguise), and medical purposes, and is one of the few mosses with a known te reo Māori name (wheuwheu) that appears to refer specifically to this species. See here for more info if you’re interested in this (it’s where I got this info from): https://rauropiwhakaoranga.landcareresearch.co.nz/names/93331f91-5442-4a5a-8c3d-f0c2c6aa08e4
Cuteness: 9/10
Distinctiveness: 9/10
LMR: 9/10
See here for today's observation of L. divulsum at Ōtepatotu: https://inaturalist.nz/observations/248218018

Another moss from Ōtepatotu: Philonotis scabrifolia. This one was growing on the cliff face, tucked into a little spot where water seeps from the rock. Moist seeps or near streams is where this P. scabrifolia is usually seen. This species is widespread through the southern hemisphere, but absent from the northern hemisphere. As you can see from these photos, P. scabrifolia has a distinctive pale blue-green colour. Two other species in the genus are found in Aotearoa, but P. scabrifolia is the only one with this colour. The branching pattern of P. scabrifolia forms an umbrella shape, although this is not always obvious (photo on the left is the one I saw yesterday, without an obvious umbrella shape, photo on the right is a different observation of the same species, with clear umbrella shape). Perhaps if this species always looked like the photo on the right it would get a higher cuteness score.
Cuteness: 7/10
Distinctiveness: 9/10
LMR: 8/10

On days spent studying on campus, I often go for walks through Riccarton Bush, which makes for a lovely study break. Riccarton Bush is the last fragment of the forest that once cloaked the Canterbury Plains remaining within the city of Christchurch. Although relatively intact, it was grazed historically. The bush seems to have a fairly low diversity of mosses. Why this is, I am not sure, but possible hypotheses include the local climate or historic grazing. Of the mosses that are present in Riccarton Bush, Racopilum cuspidigerum seems to be the most abundant. There are two varieties of this species globally, but the only variety we have in Aotearoa is Racopilum cuspidigerum var. convolutaceum This variety is common in Aotearoa and Australia, and scattered throughout the rest of the southern hemisphere. Racopilum species have a distinctive leaf arrangement with two rows of flattened leaves and a row of smaller leaves between the flattened leaves. They also have a distinctive midvein that extends well beyond the edge of the leaf. Although the genus is distinctive, R. cuspidigerum can be challenging to distinguish from another Racopilum species, R. strumiferum. In theory, R. cuspidigerum can be distinguished by lacking a margin to the leaves (whereas R. strumiferum has a faint margin), but the difference between no margin and a faint margin is not always obvious.
Cuteness: 7/10
Distinctiveness: 7/10
LMR: 7/10

Many moss species do not have any common names (names other than the formal latin name). Polytrichum juniperinum, on the other hand, has a common name in at least 18 languages (probably more, but that’s all I could find). The te reo Māori name for P. juniperinum is tōtara. Yes, the same as the tree. Although it initially seems odd that a tree and a moss have the same name, the name reflects the spiky-ness of both the tree and the moss. P. juniperinum is widespread and very common around Aotearoa and the world. It is usually found in open (non-forest) sites, but other than that is quite flexible in its habitat requirements. P. juniperinum can be distinguished from the other species of Polytrichum by its in-rolled leaf margins.
Cuteness: 4/10
Distinctiveness: 10/10
LMR: 5/10

I saw this moss yesterday, but needed a microscope to identify it, which I only had access to today. Fissidens rigidulus is a common aquatic or semi-aquatic moss species. It grows on rock or concrete in streams and water-races. Although the species is found throughout most of the southern hemisphere, the variety Fissidens rigidulus var. rigidulus (photographed here) is only found in Australasia, whilst the other variety present in Aotearoa, Fissidens rigidulus var. pseudostrictus, is only found in Aotearoa. Fissidens are widely regarded as enjoyable mosses to identify. They’re usually not super challenging to ID, but are challenging enough to require a microscope and give you a little satisfaction when you figure them out. All Fissidens have a double-layered leaf, with a lower folded portion and a main, flat portion. These leaves clasp the stem and give the plant a distinctive “Fissidens look”. Some key features of Fissidens rigidulus var. rigidulus are the strong borders to the leaves, and the way the leaves curl when dry.
Cuteness: 7/10
Distinctiveness: 8/10
LMR: 7/10

Two days ago, I wrote about Polytrichum juniperinum, so today (before you forget what P. juniperinum looks like), I thought I’d write about the other Polytrichum species in Aotearoa, Polytrichum commune. P. commune looks, at first glance, quite similar to P. juniperinum, however it can be distinguished by the fact that the margins of its leaves are not in-rolled. P. commune can also grow taller than P. juniperinum. The tallest I’ve seen P. commune is about 15 cm, but specimens with stems up to 30 cm long have been recorded. Like P. juniperinum, P. commune is widespread and common around the world. It is often seen in wetter areas than P. juniperinum, but their habitat preferences do overlap somewhat, and the two species can occasionally be seen together. Often, people unfamiliar with Aotearoa’s bryophytes seem to assume that all Polytrichum in Aotearoa is P. juniperinum, and P. commune gets forgotten about. Personally, I think P. commune is cuter and deserving of a higher moss rating than P. juniperinum
Cuteness: 7/10
Distinctiveness: 10/10
LMR: 8/10