Mountain Ash
Mountain Ash (also known as Rowan) is a fast-growing pioneer species, that grows to only a modest height (rarely over 10m tall). It is tolerant of cold and of poor soil conditions, and grows at a higher altitude than any other tree in the UK (hence its name - like the Ash it has a compound, pinnate leaf).

Leaf
The leaf is a long, compound, pinnate leaf with 9 - 15 paired leaflets. Each leaflet is serrated with many small teeth along the edge. It has small grey hairs on its underside which are shed later in the year.
The leaves turn a bright gold/orange/red colour in the autumn.

Buds, Bark and Stem
Buds are ovoid, with a touch of purple coloration. Silvery-grey to brown bark, which is smooth (and shiny when wet). Dark lenticels visible on young shoots.