Moss or bromeliad or something else in pine tree - Ask Extension
At Dry Lake camp ground outside of Steamboat Springs, CO, we saw some pine trees with this large plant ball growing around in large masses in the tree...
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Moss or bromeliad or something else in pine tree #419129
Asked August 03, 2017, 11:03 PM EDT
At Dry Lake camp ground outside of Steamboat Springs, CO, we saw some pine trees with this large plant ball growing around in large masses in the trees. It appears to have a light green, almost moss-like top with some yellow flowers with brown knarled roots on the bottom hanging in the air. A pictures is below. What is this?
Arapahoe County Colorado
Expert Response
The tree in your photo is White Fir (Abies concolor).
These growths are caused by a fungus called Fir Broom Rust (Melampsorella caryophyllacearum). Infection by this rust causes the fir tree to produce multiple growth shoots in a small area, forming "witches' brooms".
This fungus lives systemically in the fir tree. The broom produces new needles each year, but they lack chlorophyll so they appear yellow. These yellow needles are dropped/cast each late summer or fall.
Infected fir trees may have reduced growth, and may show dieback at points above the brooms. But infected fir trees may survive for many years with broom rust.
