+URTICACEAE+

+Slippery Elm. Red Elm+

_Ulmus fulva Michx._ [_Ulmus p.u.b.escens Walt._]

HABIT.--A medium-sized tree 40-60 feet high, with a short trunk 1-2 feet in diameter; spreading branches form a broad, open, flat-topped crown.

LEAVES.--Alternate, simple, 4-7 inches long, about one-half as broad; ovate-oblong; coa.r.s.ely doubly serrate; thick and firm; dark green and rough above, paler and somewhat rough beneath; petioles short, stout, hairy.

FLOWERS.--March-April, before the leaves; mostly perfect; borne on short pedicels in crowded fascicles; calyx campanulate, 5-9-lobed, green, hairy; corolla 0; stamens 5-9, with dark red anthers; stigmas 2, reddish purple.

FRUIT.--May; semi-orbicular, 1-seeded samaras, short-stalked in dense cl.u.s.ters; seed cavity brown-tomentose; wings smooth, nearly 3/4 inch long.

WINTER-BUDS.--Terminal bud absent; lateral buds ovoid, obtuse, dark brown, rusty-tomentose, 1/4 inch long.

BARK.--Twigs at first bright green and p.u.b.escent, becoming light to dark brown or grayish; thick on old trunks, dark red-brown, shallowly fissured into large, loose plates; inner bark mucilaginous.

WOOD.--Heavy, hard, strong, very close-grained, durable, easy to split while green, dark red-brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Of frequent occurrence throughout the state.

HABITAT.--Prefers stream-banks and bottom-lands; rich, moist hillsides; rocky ridges and slopes.

NOTES.--Grows more rapidly than _U. americana_.

[Ill.u.s.tration: +White Elm. American Elm. Water Elm+

1. Winter twig, 2.

2. Leaf, 1/2.

3. Flowering branchlet, 1/2.

4. Flower, enlarged.

5. Fruit, 2.]

+URTICACEAE+

+White Elm. American Elm. Water Elm+

_Ulmus americana L._

HABIT.--A tree 75-100 feet high, with a trunk diameter of 2-6 feet; commonly dividing 20-30 feet above the ground into a few large branches which rise upward and outward to form a vase-shaped outline.

LEAVES.--Alternate, simple, 4-6 inches long, one-half as broad; obovate-oblong to oval; coa.r.s.ely doubly serrate; thick and firm; dark green and rough above, pale and p.u.b.escent or glabrous beneath; petioles short and stout.

FLOWERS.--March-April, before the leaves; mostly perfect; small, brown to red; borne on slender pedicels in loose fascicles; calyx campanulate, 5-9-lobed; corolla 0; stamens 4-9, with bright red anthers; ovary 2-celled; styles 2, green.

FRUIT.--May; ovate, 1-seeded samaras, smooth both sides, hairy on the margin, 1/2 inch long, long-stemmed in crowded cl.u.s.ters.

WINTER-BUDS.--Terminal bud absent; lateral buds ovoid, acute, flattened, glabrous, brown, 1/8 inch long.

BARK.--Twigs at first light green and downy, becoming glabrous, red-brown, finally ash-gray; on old trunks thick, ash-gray, deeply fissured into broad, scaly ridges.

WOOD.--Heavy, hard, strong, tough, difficult to split, coa.r.s.e-grained, light brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Common throughout the state.

HABITAT.--Prefers deep, rich, moist loam; bottom-lands; stream-banks.

NOTES.--Grows rapidly. Long-lived. The roots run along near the surface of the ground for a great distance. An ideal street tree.

[Ill.u.s.tration: +Cork Elm. Rock Elm+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 1.

4. Flowering branchlet, 1.

5. Flower, enlarged.

6. Fruit, 1.]

+URTICACEAE+

+Cork Elm. Rock Elm+

_Ulmus racemosa Thomas_ [_Ulmus Thomasi Sarg._]

HABIT.--A large tree sometimes reaching a height of 100 feet and a trunk diameter of 5 feet, but usually somewhat smaller; strongly drooping lateral and lower branches form a narrow, oblong crown.

LEAVES.--Alternate, simple, 3-6 inches long, one-half as broad; obovate to oblong-oval, more or less dished; coa.r.s.ely doubly serrate; thick and firm; l.u.s.trous, dark green above, pale-p.u.b.escent beneath; petioles p.u.b.escent, 1/4 inch long.

FLOWERS.--March-April, before the leaves; mostly perfect; greenish; borne on slender, drooping pedicels in loose racemes; calyx campanulate, 7-8-lobed; corolla 0; stamens 7-8, with purple anthers; ovary hairy, 2-styled.

FRUIT.--May; ovate, 1-seeded samaras, p.u.b.escent all over, 1/2 inch long.

WINTER-BUDS.--Terminal bud absent; lateral buds ovoid, acute, brown, pilose, 1/4 inch long.

BARK.--Twigs at first light brown and p.u.b.escent, becoming l.u.s.trous, red-brown, finally gray-brown with corky, wing-like ridges; thick and grayish on the trunk, with wide fissures separating broad, flat, scaly ridges.

WOOD.--Heavy, very strong and tough, close-grained, light red-brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Frequent in the southern third of the Lower Peninsula.

HABITAT.--Dry, gravelly uplands; rocky ridges and slopes; heavy clay soils; river-banks.