Amelanchier canadensis

(Linnaeus) Medikus

Gesch. Bot., 79. 1793.

Common names: Eastern shadbush amélanchier du Canada
Endemic
Basionym: Mespilus canadensis Linnaeus Sp. Pl. 1: 478. 1753
Treatment appears in FNA Volume 9. Treatment on page 658. Mentioned on page 445, 648, 649, 654, 657, 660, 661.

Shrubs, 0.2–8 m. Stems 1–100, in open to dense colonies, evidently stoloniferous in var. obovalis. Leaves less than half-unfolded; petiole (5–) 10–15 (–25) mm; blade elliptic or oval to oblong or obovate, (24–) 34–48 (–67) × (12–) 18–27 (–42) mm, base subcordate, rounded, or cuneate, each margin with (0–) 6–15 (–29) teeth on proximal 1/2 and (0–) 6–12 (–17) teeth in distalmost cm, largest teeth less than 1 mm, apex subacute or obtuse to rounded and mucronate, abaxial surface densely hairy by flowering, glabrous or sparsely to moderately hairy later, adaxial glabrous or sparsely (moderately) hairy later. Inflorescences (3–) 7–10 (–15) -flowered, (6–) 15–37 (–74) mm. Pedicels: 0 or 1 (or 2) subtended by a leaf, proximalmost (1–) 5–14 (–17) mm. Flowers: sepals erect, ascending, or spreading after flowering, (0.3–) 1.8–3.1 (–4.6) mm; petals linear, elliptic, or oblong, (4–) 6–10.2 (–15) × (1.8–) 2.6–4 (–5.3) mm; stamens (15–) 19–21 (–28); styles (3–) 5 (or 6), (1.5–) 3.4–4.7 (–5.8) mm; ovary apex glabrous (or moderately hairy). Pomes purplish black or maroon-purple, 6–10 mm diam.

Distribution

V9 1131-distribution-map.jpg

N.B., N.S., P.E.I., Que., Conn., D.C., Del., Ga., Maine, Mass., Md., N.C., N.H., N.J., N.Y., Pa., R.I., S.C., Tenn., Va., Vt.

Discussion

Varieties 2 (2 in the flora).

The type specimen of Amelanchier canadensis, from Virginia or Canada, includes a single stem with five leaves and the remnants of an infructescence with three fruits. Much of the difficulty in determining the identities of specimens and species distributions owes to the limited diagnostic value of the type. The authors include A. obovalis as a variety of A. canadensis because of ecologic and morphologic similarities. W. W. Ashe (1903) described A. obovalis as a shrub of swamps and loose soils, 9–15 dm or a tree to 4 m with inflorescences 3–5 cm and proximalmost pedicels 3–9 mm at flowering and 20–30 mm in fruit. K. M. Wiegand (1912) described A. canadensis (as A. oblongifolia) as a shrub with slender, erect stems in dense fastigiate colonies with inflorescences 25–60 mm, the proximalmost pedicels 8–18 mm and scarcely longer in fruit. Wiegand was uncertain about placement of specimens of A. obovalis from the southeastern United States and stated that they appeared to be this species. The circumscription by Wiegand of A. oblongifolia and the circumscription by Ashe of A. obovalis overlap considerably. The two species co-occur in similar habitats, have overlapping phenologies, and individual populations may contain specimens with intermediate morphologic characters, especially at early successional sites. Experimental crosses between plants representing the morphologic and ecologic extremes result in formation of mature fruit and seed (C. T. Frye, unpubl.). Plants growing among rocky outcrops in the Potomac River Gorge in Maryland and Virginia suggest A. spicata in growth form and habitat but differ in having glabrous ovary apices and the finely toothed leaves of A. canadensis. These plants are also unusual in that most individuals in the population rarely produce fruits suggesting the presence of locally dominant self-incompatibility allele(s).

Selected References

None.

Key

1 Petals (4–)7–10.2(–15) mm; inflorescences (12–)21–37(–74) mm; proximalmost pedicels (6–)8–14(–17) mm; shrubs 0.5–8 m; stems in open to dense colonies. Amelanchier canadensis var. canadensis
1 Petals (5–)6–8(–10.4) mm; inflorescences (6–)15–27(–45) mm; proximalmost pedicels (1–)5–10(–15) mm; shrubs 0.2–2 m; stems in dense colonies, often evidently stoloniferous. Amelanchier canadensis var. obovalis
... more about "Amelanchier canadensis"
hairy +, glabrous +, glabrous or +  and sparsely moderately hairy +
1 cm10 mm <br />0.01 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
glabrous +  and hairy +
Christopher S. Campbell +, Michael B. Burgess +, Kevin R. Cushman +, Eric T. Doucette +, Alison C. Dibble +  and Christopher T. Frye +
(Linnaeus) Medikus +
fissuring in older trees +  and smooth +
salmon colored +, brown +  and gray +
compound +  and simple +
opposite +  and alternate +
cuneate +, rounded +  and subcordate +
Mespilus canadensis +
4.8 cm48 mm <br />0.048 m <br /> (6.7 cm67 mm <br />0.067 m <br />) +
2.7 cm27 mm <br />0.027 m <br /> (4.2 cm42 mm <br />0.042 m <br />) +
3.4 cm34 mm <br />0.034 m <br /> (4.8 cm48 mm <br />0.048 m <br />) +
oval +  and oblong or obovate +
18mm +  and 27mm +
adnate +  and connate +
Eastern shadbush +  and amélanchier du Canada +
N.B. +, N.S. +, P.E.I. +, Que. +, Conn. +, D.C. +, Del. +, Ga. +, Maine +, Mass. +, Md. +, N.C. +, N.H. +, N.J. +, N.Y. +, Pa. +, R.I. +, S.C. +, Tenn. +, Va. +  and Vt. +
not +  and aggregated +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
purplish +  and nearly black pinkish or maroon-purple dark purple-blue or brownish +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
glabrous +  and hairy +
(3-)7-10(-15)-flowered +
3.7 cm37 mm <br />0.037 m <br /> (7.4 cm74 mm <br />0.074 m <br />) +
nodding +, spreading +, drooping +, erect +, ascending +  and arching +
1.5 cm15 mm <br />0.015 m <br /> (3.7 cm37 mm <br />0.037 m <br />) +
crassinucellate +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
deciduous +
pinnate +, dentate +, serrate +  and entire +
toothed +, unlobed +  and lobed +
6-10-loculed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
1 cm10 mm <br />0.01 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
1.02 cm10.2 mm <br />0.0102 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0 (?) +  and 4 (?) +
0.4 cm4 mm <br />0.004 m <br /> (0.53 cm5.3 mm <br />0.0053 m <br />) +
Pink (?) +, Ivory (?) +  and White (?) +
free +  and distinct +
0.6 cm6 mm <br />0.006 m <br /> (1.02 cm10.2 mm <br />0.0102 m <br />) +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
adnate +, free +, connate +  and distinct +
maroon-purple +  and purplish black +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1.4 cm14 mm <br />0.014 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
Gesch. Bot., +
4-17-flowered +
not arillate +
0.31 cm3.1 mm <br />0.0031 m <br /> (0.46 cm4.6 mm <br />0.0046 m <br />) +
persistent +
free +  and distinct +
spreading +, ascending +  and erect +
triangular +  and lanceolate +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.31 cm3.1 mm <br />0.0031 m <br />) +
free +  and distinct +
stoloniferous +
erect +  and ascending +
1 +  and 100 +
0.47 cm4.7 mm <br />0.0047 m <br /> (0.58 cm5.8 mm <br />0.0058 m <br />) +
persistent +
connate +  and distinct +
basal +, lateral +, subterminal +  and terminal +
elongate +
0.34 cm3.4 mm <br />0.0034 m <br /> (0.47 cm4.7 mm <br />0.0047 m <br />) +
Amelanchier canadensis +
Amelanchier +
species +
6 +  and 15 +
inconspicuous +