Prunus spinosa

Linnaeus

Sp. Pl. 1: 475. 1753.

Common names: Blackthorn sloe
Introduced
Treatment appears in FNA Volume 9. Treatment on page 376. Mentioned on page 357, 360.

Shrubs, suckering, 10–40 dm, thorny. Twigs with axillary end buds, hairy. Leaves deciduous; petiole 4–7 mm, hairy, eglandular; blade elliptic to obovate, 1.5–4 × 1–2.2 cm, base obtuse to rounded, margins crenulate-serrulate, teeth blunt, often glandular, apex acute to obtuse, abaxial surface hairy (especially along midribs and veins), adaxial glabrate. Inflorescences usually solitary flowers, sometimes 2-flowered fascicles. Pedicels 0.5–5 (–8) mm, usually glabrous, rarely hairy. Flowers blooming before leaf emergence; hypanthium cupulate, 1.5–2.5 mm, glabrous externally; sepals spreading, oblong, 1.5–2.5 mm, margins glandular-toothed, surfaces glabrous or adaxially hairy at bases; petals white, elliptic, 4–8 mm; ovaries glabrous. Drupes bluish black, globose, 10–15 mm, glabrous; mesocarps fleshy; stones subglobose, ± flattened. 2n = 32.


Phenology: Flowering Mar–May; fruiting Aug–Sep.
Habitat: Roadsides
Elevation: 0–1000 m

Distribution

V9 623-distribution-map.jpg

Introduced; B.C., N.S., Ont., Conn., Idaho, Maine, Mass., Mich., N.Y., Oreg., Wash., Eurasia, n Africa

Discussion

As past flora writers (C. L. Hitchcock et al. 1955–1969; E. G. Voss 1972–1996) have noted, the distinctions between Prunus spinosa and P. domestica are not clear. Some researchers consider the hexaploid P. domestica to have been derived from the tetraploid P. spinosa, often in a scenario involving hybridization with P. cerasifera. It should not be surprising that some of the characters used in keys to separate these three taxa (spininess, indument, leaf size, pedicel length, numbers of flowers per bud) are subject to variation within each species and overlap among the species.

Selected References

None.

Lower Taxa

None.
... more about "Prunus spinosa"
acute;obtuse +
Joseph R. Rohrer +
Linnaeus +
dark gray +, gray-brown +, reddish-brown +  and reddish +
compound +  and simple +
opposite +  and alternate +
obtuse +  and rounded +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
elliptic +  and obovate +
0.5 cm5 mm <br />0.005 m <br /> (18 cm180 mm <br />0.18 m <br />) +
membranous +  and leathery +
1 cm10 mm <br />0.01 m <br /> (?) +  and 2.2 cm22 mm <br />0.022 m <br /> (?) +
free +  and distinct +
Blackthorn +  and sloe +
solitary +, fascicles +, 2-flowered +  and umbellate +
B.C. +, N.S. +, Ont. +, Conn. +, Idaho +, Maine +, Mass. +, Mich. +, N.Y. +, Oreg. +, Wash. +, Eurasia +  and n Africa +
not +  and aggregated +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
bluish black +
globose +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0–1000 m +
flattened +
hairy +  and glabrous +
0.4 cm4 mm <br />0.004 m <br /> (4 cm40 mm <br />0.04 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
not +  and aggregated +
Roadsides +
persistent +  and deciduous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
crassinucellate +
deciduous +
crenulate-serrulate +
glandular-toothed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and apical +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
hairy +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0 (?) +  and 4 (?) +
free +  and distinct +
rhombic;oblanceolate;rhombic;oblanceolate;ovate;oblong;usually suborbiculate;elliptic or obovate +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Flowering Mar–May +  and fruiting Aug–Sep. +
adnate +, free +, connate +  and distinct +
not arillate +
free +  and distinct +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Introduced +
free +  and distinct +
branched +  and simple +
1 +  and 20 +
linear;lanceolate +
flattened +  and subglobose +
deciduous +
distinct +
basal +, lateral +, subterminal +  and terminal +
not elongate +
hairy +  and glabrous +
Amygdalus +, Armeniaca +, Cerasus +, Lauro-cerasus +, Padus +  and Persica +
Prunus spinosa +
species +
inconspicuous +
shrub +  and suckering +
hairy +  and glabrous +