Rhabdocline laricis

Rhabdocline laricis, also known as Meria laricis, is a hyphomycete fungus in the family Cenangiaceae. In larch conifer trees (Larix), it causes the plant disease larch needle cast, also known as meria needle blight. It is generally harmless in older trees. However, it causes browning of needles, which can slow growth, weaken overall resistance to opportunistic pathogens, and can sometimes outright kill seedlings, making Rhabdocline laricis a threat in tree nurseries. The fungus is sometimes confused with the similar Hypodermella laricis, which causes larch needle blight. Both fungi can infest the same larch for a more virulent effect....read more on Wikipedia.