Prunus padus
Prunus domestica
bird cherry, European bird cherry, hackberry
common garden plum, cultivated plum, European plum, prunier damas
with terminal end buds, glabrous or puberulent.
with axillary end buds, usually hairy, sometimes glabrous.
deciduous;
petiole 8–17 mm, glabrous or puberulent on adaxial surface or both surfaces, glandular distally, glands 1–4;
blade elliptic to obovate, 5–10(–13) × 2.5–4.5(–7) cm, base obtuse to rounded or subcordate, margins serrate, teeth ascending to spreading, sharp, eglandular, apex acuminate to abruptly so, lateral veins 10–18 per side, raised abaxially, surfaces glabrous or abaxial hairy in vein axils or along midribs.
deciduous;
petiole 6–20 mm, glabrous or hairy on adaxial surface or both surfaces, eglandular or glandular distally or on margins at bases of blades, glands 1–3;
blade elliptic to obovate, (2.5–)4–7(–9) × 1.5–5 cm, base cuneate to obtuse, margins singly to doubly crenate-serrate, teeth blunt, glandular, apex usually acute to abruptly acuminate, sometimes obtuse, abaxial surface hairy (especially along veins), adaxial glabrous or midribs hairy.
15–50-flowered, racemes;
central axes 45–150 mm, leafy at bases.
solitary flowers or 2-flowered fascicles.
3–17 mm, glabrous.
(2–)10–20 mm, glabrous or hairy.
blooming after leaf emergence;
hypanthium cupulate, 2–2.5 mm, glabrous externally;
sepals broadly spreading to reflexed, oblong-ovate, 1.2–2 mm (lengths greater than widths), margins glandular-toothed, surfaces glabrous;
petals white, obovate to suborbiculate, (5–)6–9 mm;
ovaries glabrous.
blooming before or at leaf emergence;
hypanthium cupulate, 3–5 mm, glabrous externally;
sepals spreading to reflexed, ovate-elliptic to lanceolate, 3.5–6 mm, margins glandular-toothed, ciliate, surfaces glabrous or hairy;
petals white, oblong to suborbiculate, 7–14 mm;
ovaries glabrous.
black, globose, 6–8 mm, glabrous;
hypanthium deciduous, leaving discs at bases of drupes;
mesocarps fleshy;
stones subglobose, not flattened, rugulose.
blue-black (green, yellow, or red in cultivars), ellipsoid to globose, 15–35 mm, glabrous;
mesocarps fleshy;
stones ovoid to ellipsoid, strongly flattened.
= 32.
= 48.
Prunus padus
Prunus domestica
Prunus padus is cultivated in North America as an ornamental prized for its long, showy racemes of white flowers and its cold hardiness. Its value in the upper Midwest is often compromised by fungal infection causing black knot disease.
Prunus padus is difficult to distinguish from P. virginiana var. demissa, at least from herbarium material. Induments of hypanthium interior have been widely used in keys to separate the two: hairy in P. padus versus glabrous in P. virginiana. As noted by E. G. Voss (1972–1996, vol. 2), many of the specimens of P. virginiana have a pubescent hypanthium, especially basally. This is true throughout the range of P. virginiana, and also for some specimens of P. serotina. The hypanthia of P. padus are more hairy than those of P. virginiana. The petals of P. padus are longer than those of eastern chokecherry (P. virginiana var. virginiana), making it possible to distinguish flowering specimens from east of the Rocky Mountains. The petals are only slightly longer, on average, than those of P. virginiana var. demissa. Petals of P. padus are also a bit narrower and more elliptic. Shape of sepals may prove useful: 1.2–2 mm with lengths greater than widths in P. padus versus 0.7–1.4 mm with lengths equal to widths in P. virginiana var. demissa. In fruit, the difference between rugulose stones of P. padus and smooth stones of P. virginiana is subtle, perhaps too subtle for those unfamiliar with the range in variation of pit surfaces among these taxa.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The distinctions given in the literature between Prunus domestica and P. insititia, and which cultivated varieties are derived from each of them, are contradictory and confusing. After examining plants from North America, it seems best to treat these Eurasian introductions as one variable species without designation of infraspecific taxa.
European plums are grown along the West Coast, primarily in California, for prunes and other processed food. They are also grown in the Great Lakes region of Ontario, Michigan, and New York for both prunes and the local fresh market. Most of the commercial fresh plum market is supplied by fruits of the Japanese plum, Prunus salicina, and its hybrid derivatives, which include genetic material from native American species, for example, P. americana, P. angustifolia, and P. hortulana.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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