North America Native Plant

Parasite Rinodina Lichen

Botanical name: Rinodina parasitica

USDA symbol: RIPA5

Habit: lichen

Native status: Native to North America  

Parasite Rinodina Lichen: A Tiny Garden Resident You Never Planted If you’ve ever taken a close look at the bark of trees in your yard, you might have noticed small, grayish patches that look almost painted on. Meet the parasite rinodina lichen (Rinodina parasitica), a fascinating organism that’s probably been ...

Parasite Rinodina Lichen: A Tiny Garden Resident You Never Planted

If you’ve ever taken a close look at the bark of trees in your yard, you might have noticed small, grayish patches that look almost painted on. Meet the parasite rinodina lichen (Rinodina parasitica), a fascinating organism that’s probably been quietly living in your garden ecosystem without you even realizing it!

What Exactly Is a Lichen?

Before we dive into this particular species, let’s clear up what a lichen actually is. Despite the somewhat alarming parasite in its name, Rinodina parasitica isn’t actually parasitic at all. Lichens are remarkable partnerships between fungi and algae (or sometimes cyanobacteria), working together in perfect harmony. Think of it as nature’s ultimate roommate situation – the fungus provides structure and protection, while the algae handles the food production through photosynthesis.

Getting to Know Parasite Rinodina Lichen

Rinodina parasitica is what scientists call a crustose lichen, meaning it forms a thin, crusty layer that’s tightly bonded to its host surface. This native North American species appears as small, grayish to brownish patches on tree bark, often looking like someone dabbed paint across the surface in irregular patterns.

This lichen has made itself at home across various regions of North America, quietly colonizing the bark of different tree species. You’ll typically find it on the trunks and larger branches of both deciduous and coniferous trees.

Is It Good for Your Garden?

Here’s the wonderful news: having parasite rinodina lichen in your garden is actually a positive sign! Lichens are incredibly sensitive to air pollution, so their presence indicates that your local air quality is relatively clean. They’re like natural air quality monitors that work for free.

Benefits of having lichens in your garden include:

  • They don’t harm trees – despite the misleading name, they’re not parasites
  • They indicate good air quality in your area
  • They add subtle texture and natural character to tree bark
  • They’re part of a healthy, diverse ecosystem
  • Some wildlife species use lichens for nesting material

How to Identify Parasite Rinodina Lichen

Spotting Rinodina parasitica requires looking closely at tree bark. Here’s what to look for:

  • Appearance: Small, grayish to brownish crusty patches
  • Texture: Thin and tightly attached to bark surface
  • Location: On the bark of various tree species
  • Size: Individual patches are typically small, often less than an inch across
  • Pattern: Irregular, scattered patches rather than uniform coverage

Can You Grow or Encourage Lichens?

Here’s where lichen gardening gets tricky – you can’t really plant or cultivate lichens like traditional garden plants. They establish themselves naturally when conditions are right. However, you can create an environment that welcomes them:

  • Avoid using chemical treatments on tree bark
  • Maintain diverse tree species in your landscape
  • Keep your garden pesticide-free when possible
  • Support overall air quality in your community

The Bottom Line

If you discover parasite rinodina lichen growing on your trees, consider yourself lucky! These tiny organisms are indicators of a healthy environment and add to the natural complexity of your garden ecosystem. Rather than trying to remove them (which isn’t necessary and could damage tree bark), simply appreciate them as part of nature’s intricate web of life happening right in your backyard.

Remember, the best thing you can do for lichens is simply to leave them alone and maintain the clean, healthy environment they need to thrive. They’re doing their part to make your garden a more diverse and interesting place – no planting required!

Parasite Rinodina Lichen

Classification

Group

Lichen

Kingdom

Fungi - Fungi

Subkingdom
Superdivision
Division

Ascomycota - Sac fungi

Subdivision
Class

Ascomycetes

Subclass
Order

Lecanorales

Family

Physciaceae Zahlbr.

Genus

Rinodina (Ach.) A. Gray - rinodina lichen

Species

Rinodina parasitica H. Mayrh. & Poelt - parasite rinodina lichen

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