Well, sex is definitely overstating it a bit! When I and others use the word sex in connection to moss, it’s for fun or sensationalism and eyeballs.
When it comes to moss we are definitely talking about reproduction. I’ve been formulating an article about moss sex for a while but then the scientific journal Nature came out with new research and new discoveries in July. Glad I waited…

Until recently it was believed that moss relied on water and moisture to get it’s sperm to the eggs. Most moss plants are either male or female. The eggs are contained in little pod-like structures called archegoniums and the sperm have to swim with the help of water to the eggs.
Moss grows everywhere, so I don’t see how anyone could truly be concerned that moss fertilization was impossible or seriously flawed. On the other hand, based on what scientists knew about moss reproduction, fertilization seemed like a difficult proposition. Some say the moss sperm are weak and unintelligent, they scarcely live long enough make the distance to the eggs and there is also the challenge of finding the ensconced eggs with no road signs.
The new discovery is that the moss reproductive process looks a great deal like what happens with flowers, pollen and bees. Some cute micro bugs called Springtails as well as mites, act like bees traveling around, in and through the moss and the sperm are able to hitch a ride to the female eggs. And like flowers, female moss emits a chemical or scent that helps the sperm and the Springtails to find it. (Male plants have a scent as well.)
So a couple of other cool moss sex facts:
Moss is one of most ancient plants on earth and evolved from the algae in the oceans. Moss, lichen, liverworts all have sperm. Other plants do not. Scientists consider moss to be caught in a time warp; they evolved early on and then stayed the same.
In addition to water, scents and Springtails, it may be that moss sperms are released from a little pod or case, that catapults them near and far and thus reduces the distance they travel on their own. Seems like you could test this out by videotaping a moss plant continuously. Like a reality show for moss.
Scientists say the new research raises more questions than it answers. Those questions include, what’s in it for the Springtails? What do they get out of their relationship with moss? And is this kind of pollinator relationship more common then we thought? If moss & springtails do it and flowers & bees, anyone else?
What other discoveries lie ahead:)
If you are riveted by moss sex, here are my sources:
Summary of Nature Journal Article: Sex-specific Volatile Compounds Influence Microarthropod-mediated Fertilization of Moss
Droll Article on Better Sex for Moss with an Amazing Springtail Video:
How Mosses Have Sex in Spite of Their Swimming-Challenged Sperm
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Karen Nierlich is the author of I Heart Moss (Formerly Journal of a Moss Enthusiastic.) She’s looking forward to the rainy season and the opportunity to take more moss photos. She lives in Albany, CA with her husband, two kids, two cats and a dog.