Sorbus americana - American Mountain-Ash

General Information Common Name  American Mountain-ash Scientific Name  Sorbus americana Sun Tolerance  Full Sun Height  9 - 12 m (30-40 ft) Spread  6 -8 m (20 - 30 ft) Growth Rate  Fast Bloom Time  Spring Color  Green, Flower Color  White Type  Tree Native  USA, Asia, Europe.

Classification Kingdom  Plantae – Plants Subkingdom  Tracheobionta – Vascular plants Superdivision Spermatophyta – Seed plants Division  Magnoliophyta – Flowering plants Class  Magnoliopsida – Dicotyledons Subclass  Rosidae Order  Rosales Family  Rosaceae – Rose family Genus  Sorbus L. – Mountain Ash Species  S. americana

Sorbus americana - American Mountain-Ash

Sorbus americana is commonly known as the American Mountain-ash. It is a deciduous perennial tree, native to eastern North America. The American mountain-ash and related species are most often the European Mountain ash, Sorbus aucuparia referred to as rowan trees.

It is a relatively small tree, reaching 12 m (40 ft) in height. It’s bark Light gray, smooth, surface scaly. Branchlets downy at first, later become smooth, brown tinged with red, lenticular, finally they become darker and the papery outer layer becomes easily separable. The leaves of American Mountain-ash are arranged alternate, compound, odd-pinnate, 6-25 cm long, with slender, grooved, dark green or red petiole. They come out of the bud downy, conduplicate; when full grown are smooth, dark yellow green above and paler beneath. In autumn they turn a clear yellow. Stipules leaf-like, caducous.

After the leaves are full grown it blooms white flowers in Spring. The flowers are 30 mm across, borne in flat compound cymes 7-10 cm across. Bracts and bractlets acute, minute, caducous. The fruits look berry-like pome, globular, 60 mm across, bright red, borne in cymous clusters. They are start ripens in October and remains on the tree all winter. Flesh thin and sour, charged with malic acid. The seeds light brown. And oblong, compressed; cotyledons fleshy.

S. americana is cultivated as an ornamental tree in gardens and parks. 

Sorbus americana - American Mountain-Ash

Sorbus americana - American Mountain-Ash Leaves

Leaves of American Mountain-Ash

Sorbus americana - American Mountain-Ash Leaves in Autumn

Sorbus americana - American Mountain-Ash Flowers

Flowers of American Mountain-Ash

Flowers of Sorbus americana 

Sorbus americana - American Mountain-Ash Bark

Sorbus americana - American Mountain-Ash Green Fruits

Sorbus americana - American Mountain-Ash Fruits

Fruits of American Mountain-Ash

Sorbus americana - American Mountain-Ash in Autumn

Sorbus americana - American Mountain-Ash

Sorbus americana - American Mountain-Ash in Autumn

Sorbus americana - American Mountain-Ash