While the first human visitors to Mars will certainly searching for evidence of past or present life on the red planet, likely by drilling into rocks in search of microscopic signs of life, the lack of vascular plants means that future astronauts won’t be packing a plant press in their capsule.

A man in a space suit walks in front of a rock face.
Crew 143 commander Paul Knightly walks through tall stands of rabbitbrush (Ericameria nauseosa). Image: Paul Sokoloff © Canadian Museum of Nature

Still, even in the most Mars-like environments here on Earth, such as at the Mars Desert Research Station (MDRS) in southeastern Utah, USA, you can find a wide variety of vascular plants, lichens, algae and even fungi.

Documenting this diverse flora can help us understand these Martian analogs better, so when I spent two weeks in a simulated Martian mission at MDRS back in 2014, I focused each one of my “spacewalks” on collecting a wide range of “Martian” plants.

A plant growing in a rocky landscape.
The green ephedra (Ephedra viridis) is common in the deserts of Utah. The tough, jointed stems can be boiled to make tea. Image: Paul Sokoloff © Canadian Museum of Nature

This study, recently published in the open-access Biodiversity Data Journal, yielded 38 vascular plant species, 13 different lichens, six taxa of terrestrial algae and a mushroom. No doubt, if we had stayed till December we would have found the Martian equivalent of a partridge in a pear tree as well.

A large plant and several smaller ones grow in a rocky landscape with hills in the distance.
The flora of the Mars Desert Research Station includes alien invaders as well, like this introduced saltcedar (Tamarix ramosissima). Image: Paul Sokoloff © Canadian Museum of Nature

Utah contains approximately 3000 vascular plant taxa spread across a wide range of habitats, from the hot Mohave desert to cool alpine tundra. The cool deserts of southeast Utah, which do resemble Mars (if you ignore the plants, which I clearly did not), possess many plant species adapted to the dry conditions, from prickly-pear cacti (species of Opuntia) to a wide range of asters (Asteraceae family).

A boulder with lichen.
Crustose lichens, like Acarospora strigata (the white patches on the sandstone boulder pictured), are a common sight around MDRS thanks to adaptations allowing them to thrive in harsh environments. Image: Paul Sokoloff © Canadian Museum of Nature

Lichens are well suited to life in the harsh desert environment. They are adapted to resist drying out and to resist the harsh UV radiation of the sun. These tough, slow-growing organisms are important members of the local biota; the 13 species that we found in our study are certainly a small sample of what is definitely a diverse lichen flora.

Two algae cells seen through a microscope.
Even when hiding from the desert sun inside sandstone soil crusts, endolithic algae, like the Trebouxia pictured here, rely on thick, gelatinous cell walls to prevent moisture loss. Image: Paul Hamilton © Canadian Museum of Nature

Conversely, terrestrial algae and cyanobacteria hide inside of desert rocks to beat the heat, surviving on whatever sunlight is transmitted through their sheltering stone. These species, and other microbial endoliths (rock dwellers), are excellent model systems for biologists searching out past or present Martian life. By identifying how these organisms alter the rocks they live in, astrobiologists can identify if these particular changes (called biomarkers) exist in Martian rocks.

A mushroom specimen.
Desert fungi (like the Tulostoma pictured here) are an important component of biological soil crusts – living, interconnected communities of fungi, algae, lichens, and bryophytes common in the Utah deserts. These fungi only produce mushrooms, their reproductive structures, when conditions are just right. Image: Paul Sokoloff © Canadian Museum of Nature

While humans on Mars is still a few decades off, researchers from across the globe will continue to visit MDRS in preparation for that next great step. Hopefully, this study will prove to be a useful reference for biologists and Mars-hopefuls in Utah for some time to come.

Read the entire “Martian” flora, with over 40 photos of the plants, lichens, algae and fungi.