The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Klamath plum, Oregon plum, Pacific plum, Sierra or Klamath or Pacific plume, Sierra plum, western plum

black plum, Canada plum, Canadian plum, prunier noir

Habit Shrubs or trees, often suckering, 10–30(–60) dm, sometimes thorny. Shrubs or trees, sometimes suckering, 30–90 dm, moderately thorny.
Twigs

with axillary end buds, glabrous or hairy.

with axillary end buds, usually glabrous, rarely hairy.

Leaves

deciduous;

petiole 4–18 mm, glabrous or hairy, usually glandular distally, glands 1–3, discoid;

blade elliptic, oblong-ovate, or suborbiculate, 2–5(–6.5) × 1.3–3.5(–4.5) cm, base rounded or subcordate, margins singly to doubly serrulate, teeth blunt, glandular, apex usually obtuse to rounded, rarely acute, abaxial surface glabrous or hairy, adaxial glabrous or appressed-hairy.

deciduous;

petiole 8–22 mm, glabrate with hairs adaxially, sometimes glandular distally, glands 1–3, discoid;

blade broadly elliptic to obovate, (5–)7–11 × 3–6.5 cm, base obtuse to rounded or subcordate, margins doubly crenate-serrate, teeth blunt, glandular, apex abruptly acuminate, abaxial surface hairy along midribs and major veins, adaxial glabrous.

Inflorescences

2–5-flowered, umbellate fascicles.

2–4-flowered, umbellate fascicles.

Pedicels

5–15 mm, glabrous or hairy.

7–20 mm, usually glabrous, rarely hairy.

Flowers

blooming at leaf emergence;

hypanthium campanulate, 2–3.5 mm, glabrous or hairy externally;

sepals broadly spreading to reflexed, obovate, 2.2–4(–5) mm, margins glandular-toothed, sometimes obscurely so, sometimes ciliate, surfaces glabrous or hairy;

petals white, oblong-obovate, 5–10 mm;

ovaries usually glabrous, rarely hairy.

blooming before or at leaf emergence;

hypanthium red-tinged, obconic, 3–4(–5) mm, usually glabrous, rarely hairy externally;

sepals broadly spreading to reflexed, ovate, 2–4(–5) mm, margins glandular-toothed, abaxial surface usually glabrous, rarely sparsely hairy, adaxial glabrous or hairy;

petals white, often fading to pink, suborbiculate to oblong-obovate, 8–13 mm;

ovaries glabrous.

Drupes

usually red to reddish purple, sometimes yellow, globose to ellipsoid, 15–25 mm, usually glabrous, rarely puberulent;

mesocarps fleshy;

stones ovoid, ± flattened.

red, orange, or yellowish, barely glaucous, globose to ellipsoid, 15–30 mm, glabrous;

mesocarps fleshy;

stones ovoid-ellipsoid, strongly flattened.

2n

= 16.

Prunus subcordata

Prunus nigra

Phenology Flowering Mar–May; fruiting Aug–Sep. Flowering Apr–Jun; fruiting Aug–Sep.
Habitat Stream banks, dry rocky slopes, chaparral, pine-oak and juniper-oak woodlands Borders of deciduous woods, bottomland forests, roadside thickets
Elevation 100–1900 m (300–6200 ft) 10–800 m (0–2600 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; IA; IL; IN; MA; ME; MI; MN; ND; NH; NY; OH; VT; WI; MB; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Prunus subcordata shows variation in color, size, indument, and palatability of fruits, which has been the basis for recognition of taxonomic segregates. Variety kelloggii was described as a larger plant with less hairy foliage than in typical P. subcordata, and its fruits are yellow, larger, sweeter, and more pulpy. Variety rubicunda is a smaller shrub with bright red, bitter fruits. Most noteworthy is var. oregana with densely hairy ovaries and puberulent fruits, recorded only from the sparsely inhabited border region between northeastern California and adjacent Oregon. Specimens in herbaria are few and recent collections are lacking. The assignment of P. texana with hairy fruits to the plums (J. Shaw and R. L. Small 2005) makes this variant all the more interesting. Field study and collection followed by morphologic, genetic, and molecular study are needed to clarify its systematic position and significance.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

In the northeastern United States and adjacent Canada, Prunus nigra co-occurs with, and is sometimes confused with, P. americana, despite being distinct in both flower and leaf. The red-tinged hypanthia and sepals of P. nigra give the entire inflorescence a pinkish coloration even when the petals are pure white, and the sepals bear obvious glandular teeth along their margins; in P. americana the hypanthia and sepals are green and the sepals bear relatively few glandular teeth or are eglandular. The leaf marginal teeth of P. nigra are rounded and bear glands at their tips or have callus scars where the glands fell off; those of P. americana are acute and eglandular; some may have a callused tip.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 377. FNA vol. 9, p. 379.
Parent taxa Rosaceae > subfam. Amygdaloideae > tribe Amygdaleae > Prunus Rosaceae > subfam. Amygdaloideae > tribe Amygdaleae > Prunus
Sibling taxa
P. americana, P. andersonii, P. angustifolia, P. armeniaca, P. avium, P. caroliniana, P. cerasifera, P. cerasus, P. domestica, P. dulcis, P. emarginata, P. eremophila, P. fasciculata, P. fremontii, P. geniculata, P. glandulosa, P. gracilis, P. havardii, P. hortulana, P. ilicifolia, P. laurocerasus, P. lusitanica, P. mahaleb, P. maritima, P. mexicana, P. minutiflora, P. murrayana, P. myrtifolia, P. nigra, P. padus, P. pensylvanica, P. persica, P. pumila, P. rivularis, P. serotina, P. speciosa, P. spinosa, P. subhirtella, P. texana, P. tomentosa, P. umbellata, P. virginiana, P. yedoensis
P. americana, P. andersonii, P. angustifolia, P. armeniaca, P. avium, P. caroliniana, P. cerasifera, P. cerasus, P. domestica, P. dulcis, P. emarginata, P. eremophila, P. fasciculata, P. fremontii, P. geniculata, P. glandulosa, P. gracilis, P. havardii, P. hortulana, P. ilicifolia, P. laurocerasus, P. lusitanica, P. mahaleb, P. maritima, P. mexicana, P. minutiflora, P. murrayana, P. myrtifolia, P. padus, P. pensylvanica, P. persica, P. pumila, P. rivularis, P. serotina, P. speciosa, P. spinosa, P. subcordata, P. subhirtella, P. texana, P. tomentosa, P. umbellata, P. virginiana, P. yedoensis
Synonyms P. subcordata var. kelloggii, P. subcordata var. oregana, P. subcordata var. rubicunda
Name authority Bentham: Pl. Hartw., 308. (1849) Aiton: Hort. Kew. 2: 165. (1789)
Web links