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Sorbus decora (Sarg.) Schneid.

Modern name

Sorbus decora (Sarg.) C.K.Schneid.

Synonyms

Pyrus americana var. decora Sarg.; Sorbus americana Pursh, not Marsh.; Pyrus americana (Pursh) DC; P. sambucifolia of some authors, not Cham. & Schlecht.; Sorbus sambucifolia sens. Dipp., not Roem.; S. scopulina of some authors, not Greene

A shrub or a small tree up to 35 ft high; branchlets fairly densely lenticellate, more or less downy when young; winter-buds dark crimson to almost black, glutinous, outer scales glabrous except for a few marginal hairs. Leaves with five to seven pairs of leaflets; rachis broadly grooved above, downy, or glabrous except for some glands and short hairs near the insertions of the leaflets. Lateral leaflets oblong or oblong-lanceolate, the longest about 214 in. long and 78 in. wide, rather abruptly pointed, serrate, sometimes rather jaggedly toothed, glabrous and bluish green above, whitish and glabrous or slightly downy beneath (more densely so on sterile shoots). Inflorescence flat-topped, much branched, up to 6 in. wide, its branches and the pedicels more or less hairy. Flowers white, about 38 in. across. Receptacle nearly glabrous outside, sepals ciliate. Petals rounded. Styles three or four. Fruits bright scarlet or vermilion, about 716 in. wide.

Native of eastern N. America from Newfoundland to New York, perhaps farther south, west to Wisconsin and Iowa (for var. groenlandica, see below). It is fairly closely allied to S. americana, and where the two occur in the same region, S. decora grows at somewhat higher altitudes. It is said that intermediates or hybrids occur in the wild, but S. decora can usually be distinguished by its bluish green relatively broader leaflets (length:breadth ratio 2-3:1 against 312-5:1 in S. americana, according to Jones), by being acute or shortly and abruptly acuminate at the apex, and by its larger flowers and fruits. Although the two species have long been considered distinct, the fact that the epithet americana has been applied by botanists to both species has inevitably caused confusion in gardens, where S. decora has generally been known as S. (or Pyrus) americana, and indeed often still is (1979).

S. decora makes in gardens a small, bushy-crowned tree, valued more for its broad trusses of large fruits than for its autumn-colour, though the leaves do turn to orange and russet on some soils. The fruits ripen in August and are soon taken by birds in country gardens, especially in a dry season.

var. groenlandica (Schneid.) G. N. Jones S. americana var. groenlandica Schneid. – This interesting rowan is in some respects intermediate between S. americana and S. decora. It is a native of Greenland and Labrador, extending farther south at high altitudes, and is not known to be in cultivation in Britain.

A shrubby form of S. decora is in cultivation, originally distributed by Harry White of the Sunningdale Nurseries as S. sambucifolia.

S. scopulina Greene S. sambucifolia sens. Rydb., not Roem. – A shrub to about 15 ft high, often many-stemmed from the base; young shoots coated with appressed hairs; winter buds as in S. decora. Leaflets in five to seven pairs, narrowly oblong or oblong-lanceolate, the longest nearly 3 in. long and about 78 in. wide, of rather thin texture, glabrous and dark green above, glabrous or slightly downy beneath, closely and simply toothed. Inflorescence about 312 in. wide, rather densely white-hairy. Fruits as in S. decora, but sometimes bright orange.

A native of N. America from South Dakota to Alberta across the Rocky Mountains to British Columbia, south to New Mexico; described from Colorado. It was probably not in cultivation here until Dr Brian Mulligan, then Director of the University of Washington Arboretum, Seattle, sent propagation material to Messrs Marchant, who distributed plants in the 1950s. But it remains rare.

For the sorbus distributed under the name S. scopulina see under S. aucuparia.


Genus

Sorbus

Other species in the genus