Sorbus L.

Mountain Ash

From the Latin sorbum, referring to the classical name given to the fruit of Sorbus domestica.

Deciduous trees or shrubs. Leaves alternate, simple and toothed, or pinnate; stipules soon shed. Flowers in terminal flat or conical clusters, white or occasionally pink. Sepals and petals 5. Stamens 15-20. Carpels 2-5, united. Ovary inferior or half-inferior, each chamber with 2 ovules. Fruit an orange, red or white pome, of 2-5 chambers with cartilaginous walls and containing 1-2 seeds.

Grown for the attractive flowers, foliage and fruit, but mostly in specialist plant collections. Some species are susceptible to Fireblight, so growth of this genus is not encouraged. Species occasionally offered include S. alnifolia, S. americana, S. cashmiriana, S. commixta (often as 'Embley', Snowberry Rowan, which is sometimes listed under S. discolor; grown at Hillier's Nsy, UK, from seed grown at Embley Park, Hampshire, and named in 1971), S. esserteauana, S. intermedia, S. megalocarpa, S. reducta, S. thibetica 'John Mitchell', S. vestita and S. vilmorinii.Only the more commonly cultivated species are described here.

Species of Sorbaria are occasionally offered in specialist nurseries. This genus differs from Sorbus in having a superior ovary and follicular fruit.

A key is likely to confuse identification.

About 110 species of the northern hemisphere with a centre of distribution in the Himalaya.

Cuttings, a few by grafting.

Leaves mostly pinnate (simple in S. aria); ovary inferior; fruit a pome.

Mt Lofty Bot. Garden, Adelaide, had 24 taxa in 1991.

Wright (1981), McAllister (1985), Rushforth (1991).

Source: Spencer, R. (2002). Rosaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 3. Flowering plants. Dicotyledons. Part 2. The identification of garden and cultivated plants. University of New South Wales Press.

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Cultivars of uncertain origin

Sorbus 'Joseph Rock'

Fastigiate tree with reddish buds. Leaves of up to 21 leaflets. Flowers white. Fruit mostly yellow, occasionally crimson. Possibly a chance natural hybrid, raised from seeds collected by Joseph Rock in Yunnan, China, in 1932. Susceptible to Fireblight.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Rosanae
order      Rosales
family       Rosaceae
Higher taxa
Subordinate taxa
species         Sorbus aria (L.) Crantz.
species         Sorbus aucuparia L.
species         Sorbus domestica L.
species         Sorbus hupehensis Schneid.