Let's talk about sex(es), baby!

For plants, fungi, and lichens, sexual expression has a wide and sometimes surprising variety compared to those of the animal kingdom. Dan Blanchon, Curator Botany and Rob Vennell, best-selling author and Project Curator on the Natural Sciences team takes a look at some of the quirks of reproduction in botany, mycology, and lichenology.

Blog by Rob Vennell, Project Curator, and Dan Blanchon, Curator Botany of the Natural Sciences team.

Fungi

Fungi have sex but they don’t have “sexes” like animals do, rather they have different 'mating types'. The button mushroom (Agaricus bisporus) has two mating types, The corn smut (Ustilago maydis) has 50, the grey shag (Corpinus cinerea) has 12,000 and the split gill fungus (Schizophyllum commune) has around 18,000!

Split gill (Schizophyllum commune)
^{Photo by hedera.baltica via Flickr. CC BY More information ›}

Lichens

A lichen is not an individual organism, it is actually a symbiotic union of two or more species. It was traditionally thought of as a single mycobiont (fungal partner) and a single photobiont (algal or cyanobacterial partner) living together. Today, research has found it is much more complex, with multiple potential photobiont partners, and a host of other species involved in the association including, yeasts, bacteria and other microbes.

Lots of reproductive options are open to lichens - the fungus can reproduce sexually when two fungal partners come together to produce offspring, but often they are asexual, with clusters of fungal filaments and algal cells breaking off to form new lichen colonies.

Lichen on a tree

Photo by jacme31 via Flickr. CC-BY More information ›

Plants

In botany, a flower with both male and female sexual organs is described as “perfect” - a nice change from the way human sexuality and gender is often talked about. These “perfect” flowers are the norm in botany, and by far the majority of New Zealand’s trees, shrubs, herbs, and vines are considered perfect – with both male and female sexual organs found on the same flower.

Some plants like kōtukutuku (Fuchsia excorticata) are ‘gynodioecious’. They have distinct female flowers, with a mix of flowers that can be either male or female.

Other plants like Kiwifruit can have 3 sexes: males, females and males that can also bear fruit.

Kōtukutuku, Fuchsia excorticata
_{Illustration by Fanny Osbourne. Collection of Auckland Museum}

Delve deeper into the world of our ngāhere

Deep in the forest, in places you would never think to look, are some of the most remarkable creatures. Overlooked and unsung, this is the forgotten forest: a world of glow-in-the-dark mushrooms and giant mosses, where slime moulds travel the forest in search of prey.

The Forgotten Forest is a guide to the spectacular oddities of the New Zealand forest, by Robert Vennell, bestselling author of The Meaning of Trees and Secrets of the Sea.

THE FORGOTTEN FOREST

References

Brandt, K., Machado, I. C., Navarro, D. M. D. A. F., Dötterl, S., Ayasse, M., & Milet-Pinheiro, P. (2020). Sexual dimorphism in floral scents of the neotropical orchid Catasetum arietinum and its possible ecological and evolutionary significance. AoB Plants, 12(4), plaa030.

Molloy, B. P. (2019). Apomixis in indigenous New Zealand woody seed plants and its ecological and wider significance. New Zealand Journal of Ecology, 43(1), 1-11.

McGlone, M. S., & Richardson, S. J. (2023). Sexual systems in the New Zealand angiosperm flora. New Zealand Journal of Botany, 61(4), 201-231.

Subramaniam, B., & Bartlett, M. (2023). Re-imagining Reproduction: The Queer Possibilities of Plants. Integrative and Comparative Biology, icad012.