Colorful displays of three types of rust fungi are appearing on junipers in Ohio. The fungi belong to the genus Gymnosporangium and they complete part of their life-cycle on members of the plant genus Juniperus and the other part of their life-cycle on members of the family Rosaceae. In biological terms, this type of life-cycle is known as "heteroecious."
Last Wednesday, Jerry Frankenhoff (Urban Forester, Great Parks of Hamilton County) sent an e-mail message asking about red staining on the bark of sycamore trees. He wrote that he'd never seen anything like this before. I was shocked when I looked at his attached image. Likewise, I had never before seen the unusual reddening symptoms on sycamore or any other tree.