North America Native Plant

St. Jacob Texosporium Lichen

Botanical name: Texosporium santijacobi

USDA symbol: TESA

Habit: lichen

Native status: Native to North America  

Synonyms: Cyphelium santi-jacobi (Tuck.) Zahlbr. (CYSA6)   

St. Jacob Texosporium Lichen: A Tiny but Mighty Garden Ally Have you ever noticed small, crusty patches on tree bark in your yard and wondered what they were? Meet the St. Jacob texosporium lichen (Texosporium santijacobi) – a fascinating little organism that’s probably been quietly living in your landscape without ...

St. Jacob Texosporium Lichen: A Tiny but Mighty Garden Ally

Have you ever noticed small, crusty patches on tree bark in your yard and wondered what they were? Meet the St. Jacob texosporium lichen (Texosporium santijacobi) – a fascinating little organism that’s probably been quietly living in your landscape without you even knowing it!

What Exactly Is This Lichen?

First things first – lichens aren’t plants at all! They’re actually a partnership between fungi and algae, working together in perfect harmony. The St. Jacob texosporium lichen is a crusty (or crustose) lichen that forms small, grayish patches on tree bark and dead wood. You might also see it listed under its scientific synonym, Cyphelium santi-jacobi, in older botanical references.

This little survivor is native to North America and has been quietly going about its business on our continent’s trees for ages. While we don’t have specific details about its exact range, it’s part of our natural heritage and belongs here just as much as any native wildflower.

Is It Good for Your Garden?

Absolutely! While you can’t exactly plant St. Jacob texosporium lichen (more on that in a moment), having it show up naturally in your landscape is actually a wonderful thing. Here’s why:

  • It’s a sign of good air quality – lichens are sensitive to pollution
  • It adds to your garden’s biodiversity without taking up any extra space
  • It creates tiny microhabitats for other small creatures
  • It’s completely harmless to trees and won’t damage your landscape

How to Spot St. Jacob Texosporium Lichen

Keep an eye out for these identifying features:

  • Small, crusty patches that look almost painted onto bark
  • Grayish coloration
  • Tiny cup-like structures (called apothecia) that contain spores
  • Usually found on tree bark or weathered wood
  • Grows flat against its surface rather than sticking out

Can You Grow It in Your Garden?

Here’s where things get interesting – you can’t actually plant or cultivate lichens like you would a flower or shrub. They’re incredibly picky about their growing conditions and will only establish themselves when everything is just right. Trying to transplant lichens usually doesn’t work because they need that perfect balance of moisture, air quality, and the right type of surface.

But here’s the cool part: if you create a healthy, diverse landscape with minimal chemical use and good air circulation, lichens like St. Jacob texosporium might just decide to move in on their own!

Creating a Lichen-Friendly Environment

Want to encourage lichens to visit your garden naturally? Try these approaches:

  • Avoid using pesticides and fungicides near trees
  • Leave some dead branches and weathered wood in place
  • Plant native trees that provide good bark surfaces
  • Maintain good air circulation around your plants
  • Be patient – lichens grow incredibly slowly!

The Bottom Line

St. Jacob texosporium lichen might be small and easy to overlook, but it’s a valuable member of North America’s native ecosystem. While you can’t add it to your shopping list at the garden center, you can create conditions that welcome it and other beneficial organisms to your landscape. Think of it as nature’s way of giving your garden a seal of approval – when lichens show up, you know you’re doing something right!

So the next time you’re wandering around your yard, take a closer look at those tree trunks. You might just spot this tiny native treasure quietly doing its part to keep your local ecosystem healthy and thriving.

St. Jacob Texosporium Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Caliciales

Family

Caliciaceae Chevall.

Genus

Texosporium Nadv. - texosporium lichen

Species

Texosporium santi-jacobi (Tuck.) Nadv. - St. Jacob texosporium lichen

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA