"On the small branches of Juniperus spp., the fungus causes brown to reddish-brown swellings or galls one-quarter inch to two inches in diameter. These galls, commonly called cedar apples, take two years to mature. During rainy periods in May, orange gelatinous tendrils or spore horns, develop on the gall. These may extend from the gall as much as two inches. Each gall may have more than one hundred spore horns. During dry periods in May and early June, the spore horns lose their gelatinous consistency and appear inactive. However, they regain their appearance and function with the return of wet conditions. Sometime in late June the spore horns dry up and fall off. The gall persists on the tree, but does not function again. Severely infected trees may contain hundreds of individual galls."
www.ladybug.uconn.edu/factsheets/documents/AppleRustDisea...