Prunus L. (1753), in the family Rosaceae subfamily Prunoideae, contains over 200 species in the northern hemisphere. Description Trees to 30m, or shrubs, usually without thorns. The leaves are alternate, evergreen or deciduous, usually with glands on the stalk. The flowers are solitary or in bunches or spikes, white or pink. Sepals 5, joined at the base; petals 5, equal. Stamens many. Ovary superior. Carpel 1, at the base of the ovary, with 1 ovule; style 1. Pollination is by insects. The fruits are drupes with 1 hard, stony seed. Key Recognition Features The solitary ovule in the flower, and for most species the toothed leaves with glands at the base. Evolution and Relationships Prunus is by far the largest genus in the subfamily Prunoideae; the other genera are small and have reduced flowers. Because of its economic importance and diversity, the genus Prunus has often been divided into 7 separate genera. Prunus L. includes the plum and damson, with deciduous leaves and solitary or clustered flowers, and glabrous fruit, usually with a greyish bloom, and with a smooth usually slightly flattened stone. Armeniaca Duhamel includes the apricot P. armeniaca L. and P. mume Sieb. & Zucc., with deciduous, ovate leaves, solitary or clustered flowers, and glabrous or slightly velvety fruit with a smooth, usually slightly flattened stone. Padus Miller includes the bird cherry P. padus L. and the rum cherry P. serotina Ehrh., with deciduous leaves and usually more than 15 flowers in long spikes on leafy shoots. Laurocerasus Duhamel includes P. laurocerasus L. the cherry laurel, with evergreen leaves and usually more than 15 flowers in long spikes, on shoots without leaves. Cerasus Duhamel includes the edible cherry P. avium (L.) L. and the flowering cherry P. jamasakura Sieb. ex Koidz., with deciduous leaves, flowers usually in clusters, and glabrous fruit without bloom, with a smooth, round stone. Amygdalus L. includes the almonds, including P. dulcis (Mill.) D.A. Webb, with deciduous, lanceolate leaves, solitary or clustered flowers, and usually velvety fruit, dry and splitting when ripe, with a pitted, usually slightly flattened stone. Persica Duhamel includes the peach and nectarine P. persica (L.) Batsch, with deciduous, lanceolate leaves and solitary or clustered flowers, and usually velvety, fleshy, and juicy fruit, with a deeply grooved, usually slightly flattened stone; this is sometimes included in Amygdalus. Ecology and Geography In woods and on rocky hills throughout the northern hemisphere, with particular concentrations of species in Central Asia and western China. Comment This is one of the most important economic genera, both for fruit and as ornamentals. The cherries, zakura, have been revered in Japan for 5000 years, where the hanami, meaning “flower viewing” is still an important spring festival, coinciding with both the flowering of the cherries and the planting of rice. Numerous varieties have been developed from the wild species, especially from P. jamasakura; the pink-flowered ‘Kanzan’ is one of the most widely planted of all ornamental trees in Europe. Cherrywood, usually from the wild European P. avium L., is a dark wood, valuable for furniture. The North American P. serotina is the tallest species and also produces valuable timber; its fruits were used for flavouring brandy or rum. Photographs:
Prunus avium cultivar fruit
Prunus mume 'Benichidore'
Prunus x verecunda at Wisley |
