Prunus padus |
Prunus gracilis |
|
---|---|---|
bird cherry, European bird cherry, hackberry |
Oklahoma plum, Oklahoma plume |
|
Habit | Trees, not suckering, 50–150 dm, not thorny. | Shrubs, suckering, 3–15 dm, not thorny. |
Twigs | with terminal end buds, glabrous or puberulent. |
with axillary end buds, densely hairy. |
Leaves | 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 3–8 mm, densely hairy, usually eglandular, sometimes glandular distally, glands 1–3, discoid; blade usually ovate or elliptic, rarely obovate, 2–5(–7) × 1–2.5(–3.6) cm, base obtuse to cuneate, margins finely, singly or doubly serrulate, teeth sharp, usually eglandular, sometimes glandular, glands blackish, spheric, apex acute to obtuse, abaxial surface densely hairy, adaxial sparsely hairy. |
Inflorescences | 15–50-flowered, racemes; central axes 45–150 mm, leafy at bases. |
2–4(–6)-flowered, umbellate fascicles. |
Pedicels | 3–17 mm, glabrous. |
4–15 mm, hairy. |
Flowers | 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 campanulate, 2–3 mm, hairy externally; sepals erect to spreading, ovate-oblong, 1.5–2.5 mm, margins usually entire, sometimes glandular-toothed or eglandular, sometimes ciliate, surfaces hairy; petals white, oblong to obovate, 4–7 mm; ovaries glabrous. |
Drupes | black, globose, 6–8 mm, glabrous; hypanthium deciduous, leaving discs at bases of drupes; mesocarps fleshy; stones subglobose, not flattened, rugulose. |
yellow, orange, or red, slightly glaucous, globose to ellipsoid, 9–18 mm, glabrous; mesocarps fleshy; stones subglobose to ellipsoid, ± flattened. |
2n | = 32. |
|
Prunus padus |
Prunus gracilis |
|
Phenology | Flowering Apr–May; fruiting Jul–Aug. | Flowering Mar–Apr; fruiting Jun–Aug. |
Habitat | Disturbed sites | Sandy roadsides, upland thickets, open woods, waste places |
Elevation | 0–1700 m (0–5600 ft) | 100–1300 m (300–4300 ft) |
Distribution |
AK; DE; IL; MT; NJ; NY; PA; UT; WA; NB; ON; Eurasia; n Africa [Introduced in North America]
|
AR; CO; KS; LA; NM; OK; TX |
Discussion | 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.) |
Typically, sepals of Prunus gracilis are eglandular; in some specimens, glands occur along the margins. Similar glands are sometimes found on the tips of teeth along the leaf margins. The teeth are always sharp-pointed rather than blunt or rounded as they are in those plums whose leaves consistently have glandular teeth. Presence of glands on the sepals is not correlated with glands on leaf marginal teeth. Prunus gracilis, native to the southern Great Plains, is very similar to P. maritima, a plum of the eastern seaboard over 1600 km away. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 366. | FNA vol. 9, p. 380. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Amygdaleae > Prunus | Rosaceae > subfam. Amygdaloideae > tribe Amygdaleae > Prunus |
Sibling taxa | ||
Name authority | Linnaeus: Sp. Pl. 1: 473. (1753) | Engelmann & A. Gray: Boston J. Nat. Hist. 5: 243. (1845) |
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