Prunus padus
Prunus maritima
bird cherry, European bird cherry, hackberry
beach plum
with terminal end buds, glabrous or puberulent.
with axillary end buds, densely hairy to glabrate.
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 3–11 mm, usually densely hairy, rarely hairy only on adaxial surface, usually eglandular, sometimes glandular distally, glands 1–2, discoid;
blade elliptic, broadly elliptic, or obovate (orbiculate in gravesii clone), 3.5–7 × 2–4 cm, base cuneate to obtuse (rounded in gravesii clone), margins finely, usually singly, rarely doubly, serrulate, teeth sharp, usually eglandular, rarely glandular, apex acute to obtuse (rounded in gravesii clone), abaxial surface usually hairy, sometimes only on veins or glabrescent, adaxial rugose, glabrous.
15–50-flowered, racemes;
central axes 45–150 mm, leafy at bases.
2–4-flowered, umbellate fascicles.
3–17 mm, glabrous.
5–15 mm, 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 leaf emergence;
hypanthium campanulate, 2.5–3.5 mm, hairy externally;
sepals erect to spreading, ovate, 1.5–3.5 mm, margins entire, sometimes 2-fid at apices, ciliate, surfaces hairy;
petals white, oblong-obovate, 3–8 mm;
ovaries glabrous.
black, globose, 6–8 mm, glabrous;
hypanthium deciduous, leaving discs at bases of drupes;
mesocarps fleshy;
stones subglobose, not flattened, rugulose.
red, yellow, dark blue, or purplish black, glaucous, globose, 11–18 mm, glabrous;
mesocarps fleshy;
stones ovoid, slightly flattened.
= 32.
= 16.
Prunus padus
Prunus maritima
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.)
Prunus gravesii has been known from only a single locality since its description in 1897, and there may never have been more than a single, multistemmed individual. G. J. Anderson (1980) concluded that it is a mutant derivative of P. maritima. In the study by Anderson, it differed with statistical significance from other specimens of P. maritima for only 4 of 38 morphological features measured, and even for those four the range in values between the two taxa overlapped. Their leaf flavonoid chromatograms were identical. From a conservation standpoint it is of value to designate the orbiculate-leaved gravesii clone as a distinct taxonomic variety, for which the name P. maritima var. gravesii (Small) G. J. Anderson is available. Once listed by the state of Connecticut as endangered, it is now believed to be extinct in the wild. Throughout much of its original range P. maritima is threatened by oceanside development.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
WA
Flora NW
IL Wildflowers
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
Go Botany
MD Biodiversity
