Amelanchier, also known as shadbush, serviceberry, sarvisberry, juneberry, Saskatoon, shadblow, shadwood, sugarplum, and wild-plum, is a genus of about 20 species of shrubs and small deciduous trees in the Rosaceae (Rose family).
The genus is native to temperate regions of the Northern Hemisphere, growing primarily in early successional habitats. It is most diverse taxonomically in North America, especially in the northern United States and southern Canada, and is native to every state of the United States except Hawaii. Two species also occur in Asia, and one in Europe. These plants are valued horticulturally, and their fruits are important to wildlife. The systematics (taxonomy) of shadbushes has long perplexed botanists, horticulturalists, and others, as suggested by the range in number of species recognized in the genus from 6 to 33 in two recent publications . A major source of complexity comes from the occurrence of apomixis (asexual seed production), polyploidy, and hybridization.
Amelanchier species grow to 0.2–20 m tall, arborecent or suckering and forming loose colonies or dense clumps to single-stemmed. The bark is gray or less often brown, smooth or fissuring in older trees. The leaves are deciduous, cauline, alternate, simple, lanceolate to elliptic to orbiculate, 0.5–10 x 0.5–5.5 cm, thin to coriaceous, with surfaces abaxially glabrous or densely tomentose at flowering, abaxially glabrous or more or less hairy at maturity. The inflorescences are terminal, with 1–20 flowers, erect or drooping, either in clusters of one to four flowers, or in racemes with 4–20 flowers. The flowers have five white (rarely somewhat pink, yellow, or streaked with red), linear to orbiculate petals, 2.6–25 mm long, occasionally andropetalous (bearing apical microsporangia adaxially; only known in this genus in A. nantucketensis). The flowers appear in early spring, "when the shad run" according to tradition (leading to names such as "shadbush"). The fruit is a berry-like pome, red to purple to nearly black at maturity, 5–15 mm diameter, insipid to delectably sweet, maturing in summer.
Several natural hybrids also exist.
Several species are very popular ornamental shrubs, grown for their flowers, bark, and fall color. All need similar conditions to grow well, requiring good drainage, air circulation (to discourage leaf diseases), watering during drought and acceptable soil. Note that species names are often used interchangeably in the nursery trade. Many A. arborea plants that are offered for sale are actually hybrids, or entirely different species.
The wood is brown, hard, close-grained, and heavy. The heartwood is reddish-brown, and the sapwood is lighter in color. It can be used for tool handles and fishing rods.
Propagation is by seed, divisions and grafting. Serviceberries graft so readily that grafts with other genera, such as Crataegus and Sorbus, are often successful.
A taxon commonly cited as Amelanchier "lamarckii" is very widely cultivated and naturalized in Europe, where it was introduced in the 17th century; it is known to be of North American origin, probably from eastern Canada. It is not currently known to occur in the wild, and is probably of hybrid origin between A. laevis and either A. arborea or A. canadensis; it is apomictic and breeds true from seed.