Prunus is a genus of trees and shrubs in the flowering plant family Rosaceae that includes plums, cherries, peaches, nectarines, apricots, and almonds. The genus has a cosmopolitan distribution, being native to the North American temperate regions, the neotropics of South America, and temperate and tropical regions of Asia and Africa, There are 340 accepted species. Many members of the genus are widely cultivated for their fruit and for decorative purposes. Prunus fruit are drupes, or stone fruits. The fleshy mesocarp surrounding the endocarp is edible while the endocarp itself forms a hard, inedible shell called the pyrena. This shell encloses the seed, which is edible in some species, but poisonous in many others. Besides being eaten off the hand, most Prunus fruit are also commonly used in processing, such as jam production, canning, drying, and the seeds for roasting.
Prunus padus, known as bird cherry, hackberry, hagberry, or Mayday tree, is a flowering plant in the rose family. It is a species of cherry, a deciduous small tree or large shrub up to 16 metres (52 ft) tall. It is the type species of the subgenus Padus, which have flowers in racemes. It is native to northern Europe and northern and northeast Asia, and is grown as an ornamental in North America.
Peach leaf curl is a plant disease characterized by distortion and coloration of leaves and is caused by the fungus Taphrina deformans, which infects peach, nectarine, and almond trees. T. deformans is found in the United States, Europe, Asia, Africa, Australia, and New Zealand. Peach leaf curl reduces the amount of leaves and fruit produced by peach and nectarine trees.
Monilinia fructicola is a species of fungus in the order Helotiales. A plant pathogen, it is the causal agent of brown rot of stone fruits.
Taphrina is a fungal genus within the Ascomycota that causes leaf and catkin curl diseases and witch's brooms of certain flowering plants. One of the more commonly observed species causes peach leaf curl. Taphrina typically grow as yeasts during one phase of their life cycles, then infect plant tissues in which typical hyphae are formed, and ultimately they form a naked layer of asci on the deformed, often brightly pigmented surfaces of their hosts. No discrete fruit body is formed outside of the gall-like or blister-like tissues of the hosts. The asci form a layer lacking paraphyses, and they lack croziers. The ascospores frequently bud into multiple yeast cells within the asci. Phylogenetically, Taphrina is a member of a basal group within the Ascomycota, and type genus for the subphylum Taphrinomycotina, the class Taphrinomycetes, and order Taphrinales.
Chondrostereum purpureum is a fungal plant pathogen which causes Silver leaf disease of trees. It attacks most species of the rose family Rosaceae, particularly the genus Prunus. The disease is progressive and often fatal. The common name is taken from the progressive silvering of leaves on affected branches. It is spread by airborne spores landing on freshly exposed sapwood. For this reason cherries and plums are pruned in summer, when spores are least likely to be present and when disease is visible. Silver Leaf can also happen on poming fruits like apples and pears. Plums are especially vulnerable.
Gymnosporangium globosum is a fungal plant pathogen that causes cedar-hawthorn rust.
Gymnosporangium juniperi-virginianae is a plant pathogen that causes cedar-apple rust. In virtually any location where apples or crabapples (Malus) and eastern red cedar coexist, cedar apple rust can be a destructive or disfiguring disease on both the apples and cedars. Apples, crabapples, and eastern red cedar are the most common hosts for this disease. Similar diseases can be found on quince and hawthorn and many species of juniper can substitute for the eastern red cedars.
Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits.
Podosphaera leucotricha is a plant pathogen that can cause powdery mildew of apples and pears.
Taphrina deformans is a fungus and plant pathogen, and a causal agent[s] of peach leaf curl. Peach trees infected with T. deformans will experience leaf puckering and distortion, acquiring a characteristic downward and inward curl. Leaves will also undergo chlorosis, turning a pale green or yellow, and later show a red or purple tint. Fruit can either drop prematurely or show surface distortions. Severe infection can also produce lesions on the flowers. The host tree will experience defoliation if the leaves are badly diseased. If a seedling is severely infected, it may die. Almond trees display similar symptoms.
Dibotryon morbosum or Apiosporina morbosa is a plant pathogen, which is the causal agent of black knot. It affects members of the Prunus genus such as; cherry, plum, apricot, and chokecherry trees in North America. The disease produces rough, black growths that encircle and kill the infested parts, and provide habitat for insects.
Taphrina alni is a fungal plant pathogen that causes alder tongue gall, a chemically induced distortion of female alder catkins.
Taphrina padi is a fungal plant pathogen that induces the form of pocket plum gall that occurs on bird cherry. The gall is a chemically induced distortion of the fruits, which are swollen, hollow, curved and greatly elongated, without a seed or stone, but retaining the style. The twigs on infected plants may also be deformed with small strap-shaped leaves.
Taphrina wiesneri is a plant pathogen causing witch's broom, or plant gall formations, on cherry trees. It is an important pest species of the ornamental cherry Cerasus X yedoensis in Japan.
Phyllocoptes eupadi is a mite that chemically induces a pouch gall to develop as a sub-spherical distortion rising up from the upper surface of the lamina of leaves of blackthorn shrubs Prunus padus, Prunus spinosa and other Prunus species. Synonyms are Phytoptus padi Nalepa, 1890 and "Eriophyes padi ", non Eriophyes padi Domes, 2000.
Peach scab, also known as peach freckles, is a disease of stone fruits caused by the fungi Cladosporium carpophilum. The disease is most prevalent in wet and warm areas especially southern part of the U.S. as the fungi require rain and wind for dispersal. The fungus causes scabbing, lesions, and defoliating on twig, fruit, and leaf resulting in downgrade of peach quality or loss of fruits due to rotting in severe cases.
Shot hole disease is a serious fungal disease that creates BB-sized holes in leaves, rough areas on fruit, and concentric lesions on branches. The pathogen that causes shot hole disease is Wilsonomyces carpophilus.
Prunus cornuta, the Himalayan bird cherry, is a species of bird cherry native to the foothills of the Himalayas, including China and the countries of the Indian subcontinent. A medium-sized tree, it can reach 18 m. It is used for a rootstock for sweet cherries in India. Its specific epithet references the "horned" deformation of the fruit seen when a tree is afflicted with the fungal disease pocket plum gall, ascribed to the species Taphrina padi.
Taphrina betulina is a fungal plant pathogen that causes the gall, witches broom, which is a chemical infection of birch buds or the developing shoots, leading to a proliferation of growth. It was first described by Emil Rostrup in 1883 and is found in Europe, New Zealand and North America.
