Family: Ramalinaceae
Sinewed Bushy Lichen (Ramalina americana) is a small fruticose lichen forming pale gray-green tufts of flattened branching ribbons on tree bark. The branches often appear slightly twisted and sinewy, giving the lichen a delicate shrubby appearance when viewed closely. Fine powdery soredia frequently dust the surface of the branches, creating a soft matte texture that distinguishes it from smoother fruticose lichens.
In eastern North America, Ramalina americana represents the common bark-dwelling member of the Ramalina farinacea complex. It is typically encountered on exposed tree trunks and branches where good air circulation and moderate light allow the small tufted colonies to develop among other bark lichens.
For representative images and visual context, see the page: Sinewed Bushy Lichen in the Gallery section.
Description
Ramalina americana is recognized by:
- Growth form: fruticose, forming small bushy tufts
- Thallus: pale gray-green to greenish, somewhat flattened and ribbon-like
- Branches: narrow, irregularly forked, often twisted or sinewed in appearance
- Surface features: powdery soredia commonly present on branch surfaces and margins
- Underside: not distinctly differentiated from the upper surface
- Attachment: attached at a small holdfast, forming a projecting tuft from bark
Colonies typically grow a few centimeters tall and may occur singly or in small groups scattered across bark surfaces.
Substrate and Habitat
Typical substrates and settings include:
- Bark, particularly on hardwoods such as oak, maple, and elm
- Occasionally on weathered wood or fence posts
This species is most often found in:
- Moderately exposed woodland edges
- Urban or roadside trees
- Open canopies with good airflow
It commonly occurs as part of mixed bark lichen communities, often growing alongside yellow sunburst lichens (Xanthomendoza), candleflame lichens (Candelaria), and small foliose species such as Physcia.
Identification
Key features for field diagnosis:
- Color: pale gray-green rather than bright yellow or deep green
- Form: small bushy tuft with flattened ribbon-like branches
- Surface: frequently farinose with fine powdery soredia
- Underside: not clearly differentiated; branches appear similar on both sides
- Reproductive structures: apothecia uncommon in many colonies; vegetative soredia often dominate
- Chemistry: chemical spot tests rarely required in field observation
Distinguishing features:
- Evernia mesomorpha — rounder branches and usually lacking the flattened ribbon form
- Ramalina farinacea — typically longer strap-like branches and more coastal distribution
- Ramalina intermedia — often more erect and commonly associated with rock substrates
The combination of short bushy growth, flattened branches, and diffuse powdery soredia on bark is characteristic for Ramalina americana in eastern North America.
Ecology and Notes
Ramalina americana is a bark-dwelling fruticose lichen that contributes to the structural diversity of lichen communities on tree trunks. By growing outward from the bark surface, it provides microhabitats for small invertebrates and retains moisture during humid conditions.
Like many fruticose lichens, it can be somewhat sensitive to heavy air pollution but remains common in many urban and suburban areas where air quality has improved.
Observations from Minnesota suggest that the species occurs regularly on mature hardwood bark in mixed lichen communities. Several documented observations have reached Research Grade confirmation on iNaturalist, supporting its presence across the region.
References
-
Consortium of Lichen Herbaria
https://lichenportal.org -
Lichens of North America
https://lichen.com -
iNaturalist taxon page
https://www.inaturalist.org/taxa/128085-Ramalina-americana