Pinyon Pine Needle Rust
11 Sep 2022
Ink painting/drawing of Pinyon pine needle rust (Coleosporium ribicola) on golden current (Ribes aureum).
Original photo by @Disholcaspis forwarded to me by @pascal_frey. I extrapolated the missing parts of the leaf from the original photo.
N.B. there was some debate as to whether this was Coleosporium ribicola or Cronartium ribicola, but Coleosporium ribicola seems to have won: https://x.com/pascal_frey/status/1569006794101383168
The painting shows a green golden current leaf, with round yellow lesions. Where the lesions are bordered by a leaf vein, they have a flat edge ending at the vein. Concentric circles of orange dots within the yellow lesions represent the rust fungus sporulating structures.
Top: scanned image
Middle: photograph
Bottom: montage with reference image
This is one of the few plant pathogen paintings that is not a composition. It is a direct copy from a delightful photograph that was sent to me on twitter.
The painting and photograph are set side-by-side. Both show a leaf, covered in patches of concentric rings of rust spores, as though someone has painted little targets on the leaf. Some patches of rings/spores are blocked by leaf veins, resulting in half or 2/3 target circles. The painting is done in a simplified style, where the leaf is light green, the targets are yellow and orange, and the outline and major leaf veins are black.
