North America Native Plant

Bactrospora Denticulata

Botanical name: Bactrospora denticulata

USDA symbol: BADE7

Habit: lichen

Native status: Native to North America  

Synonyms: Bactrospora integrispora Seaver (BAIN14)   

Bactrospora denticulata: The Tiny Lichen That’s Actually a Garden Hero If you’ve ever noticed small, crusty patches on the bark of trees in your yard and wondered what they were, you might have been looking at Bactrospora denticulata. This fascinating organism isn’t a plant at all – it’s actually a ...

Bactrospora denticulata: The Tiny Lichen That’s Actually a Garden Hero

If you’ve ever noticed small, crusty patches on the bark of trees in your yard and wondered what they were, you might have been looking at Bactrospora denticulata. This fascinating organism isn’t a plant at all – it’s actually a lichen, and it’s doing some pretty amazing things for your garden ecosystem that you probably never knew about.

What Exactly Is Bactrospora denticulata?

Let’s clear up the confusion right away: Bactrospora denticulata isn’t something you can plant, buy at a nursery, or add to your garden wish list. It’s a lichen – a unique organism that’s actually a partnership between a fungus and algae working together. Think of it as nature’s ultimate roommate situation, where both partners benefit from the arrangement.

This particular lichen forms thin, whitish to grayish crusty patches (scientists call this growth form crustose) that you’ll typically find growing directly on tree bark. It’s so tightly attached to its host that it looks like it’s part of the bark itself.

Where You’ll Find This Little Wonder

Bactrospora denticulata is native to North America and can be found across temperate regions of the continent. It’s not picky about specific states or regions – if you have the right conditions, you might spot it in your own backyard.

You’ll also sometimes see this lichen referred to by its scientific synonym, Bactrospora integrispora, so don’t be confused if you come across that name in field guides or online resources.

Why This Lichen Is Actually Great for Your Garden

Here’s where things get really cool: Bactrospora denticulata is like a natural air quality monitor for your garden. Lichens are incredibly sensitive to air pollution, so when you see healthy lichens like this one growing on your trees, it’s actually a sign that your local air quality is pretty good. It’s nature’s way of giving your garden environment a thumbs up!

While this lichen doesn’t provide nectar for pollinators (it doesn’t have flowers), it does contribute to the overall biodiversity of your garden ecosystem in subtle but important ways. It can provide food and shelter for tiny insects and other small creatures that are part of the complex web of garden life.

How to Identify Bactrospora denticulata

Spotting this lichen takes a bit of detective work, but here are the key features to look for:

  • Thin, crusty patches that look almost painted onto tree bark
  • Whitish to light gray coloration
  • Smooth or slightly rough texture
  • Grows directly on bark surface (not hanging or leafy)
  • Often found on deciduous trees

The patches are usually quite small – often just a few inches across – so you’ll need to look closely. They’re most noticeable on smooth-barked trees where the contrast between the lichen and bark is more apparent.

Should You Encourage or Remove It?

The short answer is: leave it alone! This lichen is completely harmless to your trees and is actually a positive indicator for your garden’s environmental health. It doesn’t damage bark or harm the tree in any way – it’s simply using the bark as a surface to live on.

If you’re seeing Bactrospora denticulata in your garden, celebrate it as a sign that you’re maintaining a healthy, low-pollution environment that supports diverse life forms. There’s no need to remove it, and honestly, you couldn’t successfully transplant or cultivate it even if you wanted to.

The Bottom Line

While Bactrospora denticulata might not be the showstopper flower or dramatic foliage plant you can add to your landscape design, it’s still a valuable part of your garden’s ecosystem. Think of it as a tiny, unobtrusive environmental indicator that tells you you’re doing something right. The next time you spot those small, crusty patches on your trees, give them a nod of appreciation – they’re proof that your garden is supporting a wonderfully diverse community of life.

Bactrospora Denticulata

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Opegraphales

Family

Opegraphaceae Stizenb.

Genus

Bactrospora A. Massal. - bactrospora lichen

Species

Bactrospora denticulata (Vain.) Egea & Torrente

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