Sorbus sambucifolia

(Chamisso & Schlechtendal) M. Roemer

Fam. Nat. Syn. Monogr. 3: 139. 1847.

Common names: Aleutian mountain ash
Basionym: Pyrus sambucifolia Chamisso & Schlechtendal Linnaea 2: 36. 1827
Treatment appears in FNA Volume 9. Treatment on page 443. Mentioned on page 434, 435.

Shrubs, 10–20 dm. Stems 1–8; bark gray; winter buds blackish red to black, conic, 7–18 mm, shiny, slightly glutinous, sparsely villous distally, hairs primarily rufous. Leaves pinnately compound; stipules sometimes persistent, margins and surface hairy, hairs rufous; blade paler abaxially, shiny, green to dark green adaxially, leaflets 7–11, opposite or subopposite, lanceolate, sometimes narrowly elliptic, elliptic, oblong, or oblanceolate, 2.5–6.5 × 0.9–2.5 cm, l/w ratio 1.9–3.8, margins serrate, apex usually acute to acuminate or attenuate, sometimes obtuse, surfaces soon glabrous; leaf and leaflet axils hairy, hairs rufous. Panicles 6–23-flowered, rounded, 2.5–7 cm diam.; peduncles sparsely rufous-villous. Pedicels sparsely rufous-villous. Flowers 10–15 mm diam.; hypanthium glabrous, hypanthium plus sepals (4.5–)5–6 mm; sepals 1.5–2.9 mm, margins usually villous, hairs white and reddish mixed [white], rarely sparsely glandular; petals white to pinkish, orbiculate or ovate, 4–5 mm; stamens 20; carpels almost completely adnate to hypanthium, apex truncate or slightly conic, styles 4 or 5, 1.5–3.5 mm. Infructescences glabrous. Pomes red, ellipsoid, 10–12 × 7–9 mm, shiny, not glaucous; sepals prominent, erect. Seeds dark brown, lanceoloid, 4 × 2 mm, symmetric, not flattened. 2n = 34 (Asia).


Phenology: Flowering spring; fruiting fall.
Habitat: Slopes and meadows
Elevation: 0–100 m

Distribution

V9 746-distribution-map.jpg

Alaska, e Asia (Japan, Russian Far East [Commander Islands, Kamchatka, Kuril Islands]).

Discussion

In North America, Sorbus sambucifolia is known only from the four westernmost islands of the Aleutians, where it is allopatric from all other Sorbus. Sorbus scopulina is known from farther east in the Aleutians; sterile specimens differ in their whitish, not rufous indument, and the less deeply sunken reticulate venation on the adaxial surfaces of the leaflets.

Selected References

None.

Lower Taxa

None.
... more about "Sorbus sambucifolia"
Peter F. Zika +  and Stéphane M. Bailleul +
(Chamisso & Schlechtendal) M. Roemer +
Pyrus sambucifolia +
Aleutian mountain ash +
Alaska +, e Asia (Japan +, Russian Far East [Commander Islands +, Kamchatka +  and Kuril Islands]). +
0–100 m +
Slopes and meadows +
Flowering spring +  and fruiting fall. +
Fam. Nat. Syn. Monogr. +
Sorbus sambucifolia +
Sorbus sect. Sambucifoliae +
species +