Sorbus americana the red cascade mountain-ash, or "Sorbus americana" 'Dwarfcrown'. It is planted in gardens, and as a street tree. Sorbus americana The tree species 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 (most often the European mountain-ash, "Sorbus aucuparia") are also referred to as rowan trees. "Sorbus americana" is a relatively small tree, reaching in height. The American mountain-ash attains its largest specimens on the northern shores of Lake Huron and Lake Superior. It resembles the European mountain-ash, "Sorbus aucuparia". Native to eastern
Aphis pomi "A. pomi", especially at high temperatures. Besides occurring on apple ("Malus domestica"), "Aphis pomi" infests other plants in the family Rosaceae including pear ("Pyrus communis "), hawthorn ("Crataegus monogyna"), medlar ("Mespilus germanica"), quince ("Cydonia oblonga"), mountain ash ("Sorbus aucuparia"), rose ("Rosa") and spiraea ("Spiraea"). It is an autoecious species, completing its life cycle on a single host species. Overwintering eggs hatch in spring and the aphids colonise the growing tips of the shoots causing the edges of the leaves to curl. These aphids are all viviparous females and give birth to other wingless aphids by parthenogenesis. In June some winged