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

bigtree plum, Mexican plum

Habit Shrubs or trees, often suckering, 10–30(–60) dm, sometimes thorny. Trees, rarely suckering, 30–120 dm, sparsely thorny.
Twigs

with axillary end buds, glabrous or hairy.

with axillary end buds, usually glabrous, sometimes 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 4–18 mm, hairy, rarely only adaxially, usually glandular distally, glands 1–2(–4);

blade usually elliptic, sometimes broadly elliptic, obovate, ovate, or oblong, 6–12 × 3–7 cm, base usually obtuse to broadly rounded, sometimes subcordate, margins coarsely, doubly serrate, teeth sharp, eglandular, apex usually abruptly acuminate to acuminate, rarely acute, abaxial surface densely hairy, adaxial rugose, glabrous or hairy.

Inflorescences

2–5-flowered, umbellate fascicles.

2–5-flowered, umbellate fascicles.

Pedicels

5–15 mm, glabrous or hairy.

4–20 mm, usually glabrous, sometimes sparsely 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 leaf emergence;

hypanthium obconic, 2–4.5 mm, glabrous or hairy externally;

sepals reflexed, ovate to lanceolate, 1.5–4 mm, margins entire or irregularly or obscurely glandular-toothed, sometimes 2-fid at apices, ciliate, surfaces hairy;

petals white, sometimes turning pink, elliptic to obovate, 5–10 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.

purplish red to dark blue, glaucous, subglobose to ellipsoid, 15–30 mm, glabrous;

mesocarps fleshy;

stones ovoid-ellipsoid, strongly flattened.

Prunus subcordata

Prunus mexicana

Phenology Flowering Mar–May; fruiting Aug–Sep. Flowering Mar–Apr; fruiting Aug–Oct.
Habitat Stream banks, dry rocky slopes, chaparral, pine-oak and juniper-oak woodlands Stream bottoms, open woods, edges of woods
Elevation 100–1900 m (300–6200 ft) 10–400 m (0–1300 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; IA; IL; IN; KS; KY; LA; MO; MS; OK; TN; TX; Mexico (Coahuila, Nuevo León, San Luis Potosí, Tamaulipas)
[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.)

As L. H. Shinners (1956b) pointed out, plums from Texas determined as Prunus americana var. lanata Sudworth are not P. americana but P. mexicana. This was extrapolated by others to mean that all hairy americana-type plums, which had been called var. lanata, are P. mexicana. As a consequence, P. mexicana is often listed from states far from where it truly occurs (for example, North Carolina, Ohio, Wisconsin) and herbarium sheets of hairy P. americana can often be found filed under P. mexicana.

(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. minutiflora, P. murrayana, P. myrtifolia, P. nigra, 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) S. Watson: Proc. Amer. Acad. Arts 17: 353. (1882)
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