What are the symptoms of Metasequoia red blight?

The symptoms of Metasequoia red blight are: the disease generally starts on the lower branches and leaves of the dawn redwood (Metasequoia glyptostroboides) first, then gradually spreads upward, eventually causing the whole plant to die. On infected branches and leaves, small brown spots appear initially, later expanding into dark brown patches, after which the small twigs and dead branches turn brown and die. The disease can also spread to green twigs, forming sunken brown canker spots; if these encircle the main stem, the upper part dies; if they do not encircle the main stem, they still fail to heal over a long period, and as the main stem grows, the canker site sinks deep into the trunk, forming furrow rot, and irregular grooves develop at the base of young trees, resulting in deformity. Under humid conditions, the lesions produce small black dots. These are the fruiting bodies of the pathogen.