Amelanchier interior
Amelanchier spicata
amélanchier de l'intérieur, inland serviceberry, Wiegand's shadbush
amélanchier en épis, dwarf serviceberry, dwarf shadbush, running serviceberry, thicket shadbush
not fully unfolded;
petiole 10–30 mm;
blade broadly ovate to elliptic, 30–70 × 20–50 mm, base rounded to subcordate, each margin with 3–15 teeth on proximal 1/2 and (2–)4 or 5(–7) teeth in distalmost cm, largest teeth less than 1 mm, apex short acuminate to apiculate, abaxial surface glabrous or sparsely hairy by flowering, surfaces glabrous later.
half-unfolded;
petiole (9.5–)11.5–16(–19) mm;
blade oval to orbiculate, (22–)34–45(–61) × (13–)21–33(–52) mm, base subcordate or rounded, each margin (0–)3–9(–14) teeth on proximal 1/2 and (3 or)4–7(–11) teeth in distalmost cm, largest teeth less than 1 mm, apex acute to obtuse and sometimes mucronate, abaxial surface densely (moderately) hairy by flowering, surfaces glabrous or sparsely hairy later.
4–12-flowered, 30–75 mm.
(5 or)6–9(–14)-flowered, (11–)22–37(–52) mm.
1 or 2 subtended by a leaf, proximalmost 10–45 mm.
(0 or)1 subtended by a leaf, proximalmost 7–16(–22) mm.
sepals recurved after flowering, 2–5 mm;
petals obovate, 6–15 × 4–5 mm;
stamens 20;
styles 5, 3–5 mm;
ovary apex densely (moderately) hairy (or glabrous).
sepals recurved after flowering, (1.7–)2–3(–4.4) mm;
petals linear-oblong, (5.5–)6.5–9(–11) × (2–)2.7–4.4(–6.5) mm;
stamens (10–)20;
styles (4 or)5, (2.2–)3–3.8(–4.6) mm;
ovary apex densely hairy (or glabrous).
purple-black, 6–8 mm diam. 2n = 4x.
purple-black, 7–12 mm diam. 2n = 3x, 4x.
Amelanchier interior
Amelanchier spicata
Amelanchier interior is distinguished by its capacity to grow into a tree to ten meters and by having sparsely hairy young leaves that are often reddish and densely hairy ovary apices. E. L. Nielsen (1939) differentiated A. interior and A. wiegandii on the basis of leaves being carinate in A. wiegandii as opposed to flat in A. interior, and leaf sinuses rounded versus acute. G. N. Jones (1946) considered those differences to be slight, and he included A. wiegandii in A. interior. The authors follow Jones, but retain the common name Wiegand’s shadbush to commemorate Wiegand’s early insights about the taxonomy of Amelanchier. M. L. Fernald (1950) considered A. wiegandii as suggesting a small-leaved A. laevis but with shorter buds, fewer teeth, fewer veins, and summit of ovary heavily tomentose. P. Landry (1975) thought A. wiegandii to be the hybrid of A. arborea and A. sanguinea, and E. G. Voss (1972–1996, vol. 2) reasoned that A. interior is a hybrid swarm involving A. laevis (or sometimes A. arborea) and plants of the A. spicata and/or A. sanguinea complex. A hybrid origin of A. interior from A. laevis and A. sanguinea is reasonable given that stem height, the number of leaf teeth, and petal length are more or less intermediate between those two species. DNA sequences from ITS region indicate that A. interior (A. wiegandii) is a possible later-generation hybrid involving a member of the western North American ITS clade (which also includes A. humilis and A. sanguinea of eastern North America) and some eastern North American taxon (C. S. Campbell et al. 1997). Multiple hybrid origins, possibly from different species, may explain the variability of A. interior. Amelanchier interior has unusually large ranges of lengths for proximal pedicels, sepals, and petals. The leaves of A. wiegandii were described by Nielsen as bronze at flowering; Jones described the leaves of A. interior as green when young. The authors assume that A. interior as they interpret it is polymorphic for the color of young leaves.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Amelanchier spicata is strongly rhizomatous and has finely toothed leaves and a glabrous or densely hairy ovary apex. The species is similar to A. humilis in habit and vestiture of the ovary apices; it differs in leaf teeth, style length, style fusion, and fruit diameter. Amelanchier spicata prefers acidic soil; A. humilis is a calciphile. How A. spicata and A. nantucketensis differ is discussed under the latter.
Amelanchier oblongifolia var. micropetala B. L. Robinson was transferred to A. stolonifera as forma micropetala (B. L. Robinson) Rehder. The type of this name has petals that fall within the size range of those of A. nantucketensis, and the authors consider it a synonym of the latter.
P. M. Catling (2006) analyzed the morphology, including flowers, of Amelanchier lucida and concluded that it is distinct from A. spicata because of its shiny leaves and erect orientation of the sepals at flowering. Amelanchier lucida closely resembles A. spicata in overall habit, leaves, inflorescences, and fruits, and the authors have observed somewhat lustrous leaves in A. spicata. The authors, therefore, include A. lucida in A. spicata.
Informally recognized, Amelanchier "maritima" is a well-studied microspecies restricted to the Atlantic Coast from Massachusetts to mid Maine. This microspecies resembles A. spicata in habit and mature leaf characters and differs significantly with longer inflorescences, more flowers per inflorescences, and longer and wider petals.
M. L. Fernald (1950) and L. Cinq-Mars (1971) reported hybrids between Amelanchier spicata and A. arborea, A. bartramiana, A. intermedia, A. laevis, and A. sanguinea. Plants determined to be apomictic and attributed to this species by C. S. Campbell et al. (1987) were actually A. nantucketensis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
MI Flora
MN Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
Go Botany
MD Biodiversity
