R. Fraley

Cedar-apple Rust

Cedar-apple Rust gall on juniper with orange gelatinous telial horns

Orange Telial Horns
Dry brown Cedar-apple Rust gall on juniper showing pitted gall surface

Dry Gall Stage
Cedar-apple Rust gall with orange telial horns hanging from a juniper branch against blue sky

Rust Gall Against the Sky
Several Cedar-apple Rust galls with orange telial horns on juniper branches

In the Cedar
Cedar-apple Rust gall with orange gelatinous horns among green juniper foliage

Orange Horns in Foliage

Gymnosporangium

Cedar-apple rust is one of the most recognizable rust fungi in the spring landscape. On juniper or eastern red cedar, the fungus forms rounded brown galls that can suddenly transform after wet weather, sending out soft orange gelatinous telial horns. These photographs show both the hard pitted gall and the hydrated orange stage, making the set useful for showing the fungus as a changing seasonal structure rather than a single static form.

For identification details and comparison with similar species, see Gymnosporangium in the Field Notes section.

Cedar-apple Rust gall on juniper with orange gelatinous telial horns

Orange Telial Horns
A close view of the hydrated orange horns emerging from a Cedar-apple rust gall on juniper/cedar foliage.
Camera: Canon EOS 5D Mark IV
Lens: EF100-400mm f/4.5-5.6L IS USM
Settings: ISO 400 • Aperture f/13.0 • Shutter 1/200 s
E22A1292 • Size: 4912×3275

Dry brown Cedar-apple Rust gall on juniper showing pitted gall surface

Dry Gall Stage
The hard brown gall shows the pitted surface and horn emergence points before or after full hydration.
Camera: Canon EOS 5D Mark IV
Lens: EF100mm f/2.8L Macro IS USM
Settings: ISO 200 • Aperture f/8.0 • Shutter 1/200 s
E22A1393 • Size: 3637×2425

The orange horns are the most dramatic part of the cedar/juniper stage, but the dry gall is equally important for identification. The pitted surface of the brown gall marks where the horns emerge when moisture returns. Together, the images show the contrast between the dormant-looking gall and the active, spore-producing stage.

Several Cedar-apple Rust galls with orange telial horns on juniper branches

In the Cedar
A wider in-place view showing multiple active galls among the surrounding juniper/cedar foliage.
Camera: Canon EOS 5D Mark IV
Lens: EF100-400mm f/4.5-5.6L IS USM
Settings: ISO 800 • Aperture f/13.0 • Shutter 1/200 s
E22A1290 • Size: 3502×2335

Cedar-apple Rust gall with orange gelatinous horns among green juniper foliage

Orange Horns in Foliage
A closer view of the orange gelatinous horns emerging among green juniper foliage.
Camera: Canon EOS 5D Mark IV
Lens: EF100-400mm f/4.5-5.6L IS USM
Settings: ISO 800 • Aperture f/8.0 • Shutter 1/800 s
E22A3323 • Size: 4896×3264

Several galls may become active on the same juniper branch, especially after wet spring weather. Wider views show how conspicuous the orange horns can be among the green foliage, while closer views emphasize the gelatinous texture and the rounded gall beneath.

Cedar-apple Rust gall with orange telial horns hanging from a juniper branch against blue sky

High in the Cedar
Orange telial horns hang from a gall high in the cedar, silhouetted against the open blue sky.
Camera: Canon EOS 5D Mark IV
Lens: EF100-400mm f/4.5-5.6L IS USM
Settings: ISO 400 • Aperture f/13.0 • Shutter 1/200 s
E22A1295 • Size: 4912×3275