Championing the ‘cute underdog’ of the plant world

There’s more to mosses than most might imagine, PhD candidate Jess Paull says.

“I feel like mosses are definitely the underdogs of plants.”

Hailing from Nevada, and more recently California, Jess arrived in Aotearoa in 2019 for her first year at Otago University. She is now one year into her PhD, focusing on a plant group most people don’t give a second glance.

“Mosses are not as insignificant as some people seem to think they are.”

Jess is working on a  researching the fungal associates of mosses, an area she says has been under-researched. Botanist know that there are fungal associates of other types of plants, and Jess hopes to determine if mosses feature as a “link on that chain”.

She credits Botany Department’s Herbarium technician, John Steele, with introducing her to moss.

“He was the one who showed me how to look at all different kinds of plants, but he also kept a very unbiased perspective.”

Jess says he pointed out that while Aotearoa’s trees are beautiful, there are also many other plants that might go unnoticed, like moss.

“I’ll always be thankful to John Steele for sharing the world of mosses with me.”

Aotearoa is a great country to study mosses in, Jess says.

“We have a lot of those special mosses here, that aren’t necessarily in other places, like, we have the tallest moss in the world – Dawsonia superba.”

Found mostly on the West Coast, Dawsonia superba can grow to about two metres high and is known as ‘trainee rimu’ because when people are learning about plants, many mistake Dawsonia superba for a rimu sapling.

“It’s a moss that can be quite substantial, so that’s a very special moss.”

Because many mosses diversified from each other during the time of Gondwana hundreds of millions of years ago, they tend to be more similar between places than vascular plants.

“That’s why New Zealand has a lot of unique trees compared to Australia. But a lot of our mosses are shared.”

Mosses are one of the oldest plant groups, are abundant in nearly all habitats, and despite their size, they have powerful consequences within environments, she says.

“And that's exactly why I think it's important to look at them in more detail. Even though they're small and simple, they are so complex in their simplicity as well.”

One thing that makes moss unique is it is haploid-dominant, meaning they have one set of chromosomes instead of two.

“This effects their entire reproductive framework and sets it apart from most other organisms.”

Most mosses don’t have roots, with all of their nutrients and water coming straight from the atmosphere.

“That's what allows them to grow in very unique places, you know right on bare rock. And what allows them to be the primary substrate for a lot of other plants. So we wouldn't have other plants without moss.”

When there is disturbance within a site, moss are often the first plant to “come in and start to create new soil”, and they help keep climatic conditions stable.

“Mosses are completely critical, and I think because they’re small, their role is not appreciated. They're a nutrient source for a lot of other plants.

“I think a lot of people see a green patch and think, ‘oh, cool, moss’. But there are  actually so many different kinds of moss, and they all do slightly different things.

“Like as a group, they're just as diverse as the other terrestrial plants. You wouldn't confuse an oak tree for a daisy. Mosses are just as different.”

Mosses are diverse and “very beautiful”.

“I would hope people look a bit closer… and appreciate that they’re there, and they’re doing things.”

A particular moss family Jess is fond of is Orthotrichaceae .

“They have very twisted leaves when dry, and it’s a treat to watch them rehydrate and come to life before your eyes.

“I find them really cute, they grow on other trees and rocks, and they just look so cute. And their cells are very unique.”