Mägimänni iseloomutunnusteks on laiuv kuju ja kaarjased oksad. Ta kasvab maapinnal laiuva laiuva põõsana 1-4 meetri pikkuseks. Okkad on tumerohelised. Eelistab päikselist kohta ning on talvega leplik.
The characteristic features of the Mountain Ash are its spreading shape and curved branches. It grows as a shrub-like bush on the ground, reaching 1-4 meters in length. The branches are dark brown. It prefers sunny locations and is deciduous.
