Prunus padus
Prunus cerasus
bird cherry, European bird cherry, hackberry
cerisier acide, cultivated sour cherry, pie cherry, sour cherry
with terminal end buds, glabrous or puberulent.
with terminal end buds, 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 10–24 mm, glabrous, usually eglandular, sometimes with discoid marginal glands at bases of blades;
blade broadly elliptic to ovate or obovate, 4.4–6(–8) × 2.8–4(–6) cm, base obtuse to rounded, margins doubly crenate-serrate, teeth blunt, glandular, apex acute to abruptly acuminate, abaxial surface glabrous or glabrate, adaxial glabrous.
15–50-flowered, racemes;
central axes 45–150 mm, leafy at bases.
1–4-flowered, umbellate fascicles.
3–17 mm, glabrous.
8–37 mm, glabrous.
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 at leaf emergence;
hypanthium tubular-campanulate, 4–6 mm, glabrous externally;
sepals reflexed, oblong, 4–7 mm, margins regularly glandular-toothed, surfaces glabrous;
petals white, suborbiculate, 10–14 mm;
ovaries glabrous.
black, globose, 6–8 mm, glabrous;
hypanthium deciduous, leaving discs at bases of drupes;
mesocarps fleshy;
stones subglobose, not flattened, rugulose.
bright red, globose, 13–20 mm, glabrous;
mesocarps fleshy;
stones subglobose, not flattened.
= 32.
= 32.
Prunus padus
Prunus cerasus
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.)
Cultivars of Prunus cerasus with doubled flowers are used as landscape ornamentals. Most of the commercial sour cherry crop in North America comes from Michigan. Unlike sweet cherry, all widely grown varieties of sour cherry are self-fertile. Bud scales at the bases of the pedicels on flowering and immature fruiting specimens of P. cerasus often have leaflike apices and the inner scales are erect; in P. avium the scales are not leaflike and the inner ones are reflexed or spreading.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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