Amelanchier alnifolia

(Nuttall) Nuttall ex M. Roemer

Fam. Nat. Syn. Monogr. 3: 147. 1847.

Common names: Alder-leaved shadbush saskatoon saskatoon berry amélanchier à feuilles d'aulne
Endemic
Basionym: Aronia alnifolia Nuttall Gen. N. Amer. Pl. 1: 306. 1818
Treatment appears in FNA Volume 9. Treatment on page 651. Mentioned on page 442, 648, 649, 652.

Shrubs, 1–12 m. Stems 1–50, solitary or colonial. 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. Inflorescences (4–) 6–11 (–16) -flowered, (8–) 14–43 (–62) mm. Pedicels: (0 or) 1 or 2 (or 3) subtended by a leaf, proximalmost (2–) 3–20 (–29) 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). Pomes black or purple, 8–15 mm diam.

Distribution

V9 1117-distribution-map.jpg

Alta., B.C., Man., N.W.T., Ont., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Iowa, Kans., Minn., Mont., N.Dak., N.Mex., Nebr., Nev., Oreg., S.Dak., Tex., Utah, Wash., Wyo.

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).

Selected References

None.

Key

1 Ovary apices glabrous (or sparsely hairy); shrubs 1–2(–4) m. Amelanchier alnifolia 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. Amelanchier alnifolia var. alnifolia
2 Inflorescences (8–)14–26(–35) mm; proximalmost pedicels (2 or)3–8(–13) mm. Amelanchier alnifolia var. semiintegrifolia
... more about "Amelanchier alnifolia"
hairy +  and glabrous +
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 +
(Nuttall) Nuttall ex M. Roemer +
fissuring in older trees +  and smooth +
salmon colored +, brown +  and gray +
compound +  and simple +
opposite +  and alternate +
cuneate +, tapering +, usually subcordate +  and truncate +
Aronia alnifolia +
4.7 cm47 mm <br />0.047 m <br /> (6.7 cm67 mm <br />0.067 m <br />) +
3.6 cm36 mm <br />0.036 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
2.4 cm24 mm <br />0.024 m <br /> (4.7 cm47 mm <br />0.047 m <br />) +
quadrangular +, usually elliptic +  and oval +
17mm +  and 36mm +
adnate +  and connate +
Alder-leaved shadbush +, saskatoon +, saskatoon berry +  and amélanchier à feuilles d'aulne +
Alta. +, B.C. +, Man. +, N.W.T. +, Ont. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Idaho +, Iowa +, Kans. +, Minn. +, Mont. +, N.Dak. +, N.Mex. +, Nebr. +, Nev. +, Oreg. +, S.Dak. +, Tex. +, Utah +, Wash. +  and Wyo. +
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 +
(4-)6-11(-16)-flowered +
4.3 cm43 mm <br />0.043 m <br /> (6.2 cm62 mm <br />0.062 m <br />) +
nodding +, spreading +, drooping +, erect +, ascending +  and arching +
1.4 cm14 mm <br />0.014 m <br /> (4.3 cm43 mm <br />0.043 m <br />) +
crassinucellate +
deciduous +
pinnate +, dentate +, serrate +  and entire +
toothed +, unlobed +  and lobed +
6-10-loculed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
2 +  and 1 +
1 cm10 mm <br />0.01 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
1.4 cm14 mm <br />0.014 m <br /> (1.88 cm18.8 mm <br />0.0188 m <br />) +
0 (?) +  and 4 (?) +
0.52 cm5.2 mm <br />0.0052 m <br /> (0.66 cm6.6 mm <br />0.0066 m <br />) +
Pink (?) +, Ivory (?) +  and White (?) +
free +  and distinct +
0.95 cm9.5 mm <br />0.0095 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
0.33 cm3.3 mm <br />0.0033 m <br /> (0.52 cm5.2 mm <br />0.0052 m <br />) +
1.91 cm19.1 mm <br />0.0191 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
0.68 cm6.8 mm <br />0.0068 m <br /> (1.91 cm19.1 mm <br />0.0191 m <br />) +
adnate +, free +, connate +  and distinct +
purple +  and black +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
2 cm20 mm <br />0.02 m <br /> (2.9 cm29 mm <br />0.029 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Fam. Nat. Syn. Monogr. +
4-17-flowered +
not arillate +
0.4 cm4 mm <br />0.004 m <br /> (0.49 cm4.9 mm <br />0.0049 m <br />) +
persistent +
free +  and distinct +
erect +  and recurved +
triangular +  and lanceolate +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
free +  and distinct +
branched +  and simple +
colonial +  and solitary +
erect +  and ascending +
1 +  and 50 +
0.29 cm2.9 mm <br />0.0029 m <br /> (0.39 cm3.9 mm <br />0.0039 m <br />) +
persistent +
connate +  and distinct +
basal +, lateral +, subterminal +  and terminal +
elongate +
0.2 cm2 mm <br />0.002 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
Amelanchier alnifolia +
Amelanchier +
species +
0 +  and 3 +
inconspicuous +