Trees or shrubs, with alternate pinnate leaves, serrate leaflets, deciduous stipules, and perfect regular white flowers, in terminal compound cymes. Calyx-tube urn-shaped, 5-lobed, not bracteolate. Petals 5, spreading, short-clawed. Stamens ∞. Ovary inferior; styles usually 3, distinct; stigma truncate; ovules 2 in each cavity. Fruit a small red berry-like pome, its carpels not cartilaginous. [The ancient Latin name of the pear or service-tree.]

A genus of about 10 species, natives of the north temperate zone. Besides the following, 2 others occur in western North America. Type species: Sorbus domesiica L.

Leaflets long-acuminate; fruit 2"-3" in diameter.

1.

S. americana.

Leaflets obtuse or short-oointed: fruit about 4" in diameter.

2.

S. scobulina.

1. Sorbus Americāna Marsh. American Mountain Ash. Dogberry

Fig. 2318

Sorbus americana Marsh. Arb. Am. 145. 1785. Sorbus microcarpa Pursh, Fl. Am. Sept. 341. 1814. Pyrus americana DC. Prodr. 2: 637. 1825.

A small tree, with smooth bark, reaching a maximum height of 300 and a trunk diameter of 18'. Leaf-buds acute; leaves petioled; leaflets 11-17, lanceolate, long-acuminate, glabrous on both sides or slightly pubescent when young, bright green above, generally paler beneath, 1 1/2-4' long, sharply serrate with mucronate teeth; cymes densely compound, 3'-6' broad; flowers 2"-3" broad; fruit globose, bright red, 2"-3" in diameter.

In low woods or moist ground, Newfoundland to Manitoba, south, especially along the mountains, to North Carolina and to Michigan. Wood soft, light brown; weight per cubic foot 34 lbs. American rowan- or service-tree. Witch- or round-wood. Round- or wine-tree. Elder-leaved mountain-ash or -sumach. Moose-missy. Missey-moosey. Indian-mozamize. Life-of-man. A closely related form occurs in Japan. May-June.

1 Sorbus Americ Na Marsh American Mountain Ash Dog 660

2. Sorbus scopulina Greene. Western Mountain Ash. Fie. 2319.

S. scopulina Greene, Pittonia 4: 130. 1900. S. subvestita Greene, loc. cit. 1900.

A small tree or often a shrub, closely resembling the preceding species. Leaf-buds acute; leaflets 7-15, proportionately broader and shorter, oval or ovate-lanceolate, obtuse or short-pointed at the apex, sharply serrate, glabrous and dark green above, pale and usually more or less pubescent beneath, especially along the veins, seldom over 3' long; flowers 3"-5" broad; calyx and pedicels generally pubescent; cymes 2'-4' broad; fruit globose, red, about 4" in diameter.

In moist ground, Labrador to Alaska, south to Maine, Pennsylvania, Michigan, and in the Rocky Mountains to Colorado and Utah. Wood similar to that of the preceding; weight per cubic foot 37 lbs. United, in our first edition, as by other authors, with S. sambucifolia (C. & S.) Roem., of eastern Asia, which proves to be distinct; it has also been referred to the northwestern Sorbus sitchensis Roem. American rowan-tree. June-July.

Sorbus Aucupāria L., the European mountain ash, rowan tree or quick-beam, has the leaves pubescent on both sides, especially when young, the calyx and pedicels usually woolly. Often planted; locally escaped from cultivation.

1 Sorbus Americ Na Marsh American Mountain Ash Dog 661