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alder-leaf shadbush, amélanchier à feuilles d'aulne, saskatoon, saskatoon berry, saskatoon serviceberry, service berry, western serviceberry

amélanchier de Fernald, Fernald's shadbush

Habit Shrubs, 1–12 m. Stems 1–50, solitary or colonial. Shrubs, 0.5–1 m, rhizomatous.
Stems

1–50, usually forming colonies.

Leaves

mostly unfolded;

petiole (3–)6.8–19.1(–28) mm;

blade usually elliptic to oval to suborbiculate, sometimes quadrangular, (14–)24–47(–67) × (7–)17–36(–55) mm, base usually subcordate to truncate, sometimes ± tapering or ± cuneate, each margin with 0–3(–9) teeth on proximal 1/2 and (0–)3–5(–8) teeth in distalmost cm, largest teeth more than 1 mm, apex rounded to truncate or occasionally acute or mucronate, abaxial surface sparsely to densely hairy (or glabrous) by flowering, sparsely to moderately hairy (or glabrous) later, adaxial glabrous or sparsely (moderately) hairy later.

mostly or fully unfolded;

petiole 1–25 mm;

blade elliptic-oblong to oblong-obovate, 50–80 × 15–45 mm, base rounded to subcordate, each margin with 4–18 teeth on proximal 1/2 and 5–10 teeth in distalmost cm, largest teeth less than 1 mm, apex subacute to rounded or mucronate, abaxial surface glabrous (or sparsely hairy) by flowering, surfaces glabrous later.

Inflorescences

(4–)6–11(–16)-flowered, (8–)14–43(–62) mm.

3–8-flowered, 20–40 mm.

Pedicels

(0 or)1 or 2(or 3) subtended by a leaf, proximalmost (2–)3–20(–29) mm.

usually 1 subtended by a leaf, proximalmost 15–35 mm.

Flowers

sepals erect to recurved after flowering, (1.4–)2.2–4(–4.9) mm;

petals oblanceolate to oval or obovate to elliptic, (5.7–)9.5–14(–18.8) × (2.2–)3.3–5.2(–6.6) mm;

stamens (10–)15–21(–22);

styles (3 or)4 or 5(or 6), (1.3–)2–2.9(–3.9) mm;

ovary apex moderately to densely hairy (or glabrous).

sepals ascending or spreading after flowering, 3–5 mm;

petals oval to broadly oblanceolate, 8–15 × 3–6 mm;

stamens 20;

styles 5, length unknown;

ovary apex densely hairy.

Pomes

black or purple, 8–15 mm diam.

dark purple or almost black, 6–10 mm diam.

Amelanchier alnifolia

Amelanchier fernaldii

Phenology Flowering Jun–Jul; fruiting Jul–Aug.
Habitat Ravines, thickets, barrens, rocky banks, shores, sea cliffs, swamps, wet woods, often calcareous
Elevation 0–100 m (0–300 ft)
Distribution
from FNA
AK; AZ; CA; CO; IA; ID; KS; MN; MT; ND; NE; NM; NV; OR; SD; TX; UT; WA; WY; AB; BC; MB; NT; ON; SK; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
NB; NF; NS; PE; QC
[BONAP county map]
Discussion

Varieties 3 (3 in the flora).

Amelanchier alnifolia is widespread and polymorphic, and its taxonomic and geographic limits have been viewed differently. L. Cinq-Mars (1971) considered this species to range eastward to the Gaspé Peninsula. Disagreements about the boundary between A. alnifolia and A. humilis are evident in herbarium specimen annotations. The distinctness of the varieties of A. alnifolia has also been questioned. G. N. Jones (1946) treated the three varieties recognized here as distinct species and noted that the leaves of var. alnifolia and var. semiintegrifolia (A. florida) are virtually indistinguishable, and, although petal lengths of the two do not overlap, occasional larger-flowered var. alnifolia and occasional smaller-flowered var. semiintegrifolia occur, so the petal length distinction is not an absolute one. Geographically these two varieties are largely separate, with var. alnifolia occurring in the Great Plains and Rocky Mountains and var. semiintegrifolia on the Pacific slopes of mountains from Alaska to northern California.

Amelanchier alnifolia is thought to hybridize with Sorbus scopulina (x\Amelasorbus jackii Rehder).

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

The rhizomatous habit, leaves that are glabrous upon expanding, and densely hairy ovary apices in Amelanchier fernaldii are a distinctive combination of characteristics. Its relationships to congeners are unclear. Access to flowering material clearly assignable to A. fernaldii has not been available, and the size of floral parts was taken from M. L. Fernald (1950).

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

Key
1. Ovary apices glabrous (or sparsely hairy); shrubs 1–2(–4) m.
var. pumila
1. Ovary apices moderately to densely hairy (or glabrous); shrubs or trees, 1–12 m
→ 2
2. Inflorescences (8–)26–43(–62) mm; proximalmost pedicels (5–)8–16(–29) mm.
var. alnifolia
2. Inflorescences (8–)14–26(–35) mm; proximalmost pedicels (2 or)3–8(–13) mm.
var. semiintegrifolia
Source FNA vol. 9, p. 651. FNA vol. 9, p. 655.
Parent taxa Rosaceae > subfam. Amygdaloideae > tribe Maleae > Amelanchier Rosaceae > subfam. Amygdaloideae > tribe Maleae > Amelanchier
Sibling taxa
A. amabilis, A. arborea, A. bartramiana, A. canadensis, A. cusickii, A. fernaldii, A. gaspensis, A. humilis, A. interior, A. intermedia, A. laevis, A. nantucketensis, A. nitens, A. pallida, A. sanguinea, A. spicata, A. utahensis
A. alnifolia, A. amabilis, A. arborea, A. bartramiana, A. canadensis, A. cusickii, A. gaspensis, A. humilis, A. interior, A. intermedia, A. laevis, A. nantucketensis, A. nitens, A. pallida, A. sanguinea, A. spicata, A. utahensis
Subordinate taxa
A. alnifolia var. alnifolia, A. alnifolia var. pumila, A. alnifolia var. semiintegrifolia
Synonyms Aronia alnifolia
Name authority (Nuttall) Nuttall ex M. Roemer: Fam. Nat. Syn. Monogr. 3: 147. (1847) Wiegand: Rhodora 22: 149. (1920)
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