Michigan Trees Part 44

HABITAT.--Prefers moist, well-drained soil on the borders of streams and swamps, often in the shade of other trees.

NOTES.--Hardy throughout the state. Easily transplanted. The only _Cornus_ with alternate leaves and branches.

[Ill.u.s.tration: +Black Gum. Pepperidge+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 3/4.

4. Staminate flowering branchlet, 1/2.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, 1/2.

7. Pistillate flower, enlarged.

8. Fruit, 1/2.]

+CORNACEAE+

+Black Gum. Pepperidge+

_Nyssa sylvatica Marsh._ [_Nyssa multiflora w.a.n.g._]

HABIT.--A medium-sized tree 40-50 feet high, with a trunk diameter of 1-2 feet, forming a rounded to cylindrical crown of slender, spreading, pendulous branches and a stiff, flat spray.

LEAVES.--Alternate, simple, 2-5 inches long, one-half as broad; oblong-obovate to oval; entire, or sometimes wavy-margined; thick and firm; very l.u.s.trous and dark green above, pale and often hairy beneath, turning bright scarlet, on the upper surface only, in autumn; petioles short.

FLOWERS.--May-June, with the leaves; polygamo-dioecious; greenish; borne on slender, downy peduncles; the staminate slender-pedicelled, in many-flowered heads; the pistillate sessile, in several-flowered cl.u.s.ters; calyx cup-shaped, 5-toothed; petals 5; stamens 5-10; stigma stout, terete, recurved.

FRUIT.--October; fleshy drupes, ovoid, blue-black, about 1/2 inch long, sour, in cl.u.s.ters of 1-3.

WINTER-BUDS.--1/8-1/4 inch long, ovoid, obtuse, dark red.

BARK.--Twigs greenish or light brown, smooth or often downy, becoming smooth, dark red-brown; thick, red-brown on old trunks, deeply furrowed.

WOOD.--Heavy, soft, strong, very tough, difficult to split, not durable in contact with the soil, pale yellow, with thick, whitish sapwood.

DISTRIBUTION.--Frequent in the southern half of the Lower Peninsula. Has been reported as far north as Manistee.

HABITAT.--Prefers the borders of swamps and low, wet lands. Rarely flourishes in exposed situations.

NOTES.--Of great ornamental value. Not easily transplanted. Pith of twigs with thin, transverse part.i.tions.

+SUMMER KEY TO THE SPECIES OF FRAXINUS+

a. Lateral leaflets sessile. _F. nigra_, p. 221.

aa. Lateral leaflets petioluled.

b. Twigs, petioles and lower sides of leaves p.u.b.escent. _F.

pennsylvanica_, p. 215.

bb. Twigs, petioles and lower sides of leaves essentially glabrous.

c. Twigs prominently 4-angled. _F. quadrangulata_, p. 219.

cc. Twigs terete.

d. Lower sides of leaves essentially of the same color as the upper; leaflet-margins rather finely sharp-serrate. _F.

pennsylvanica lanceolata_, p. 217.

dd. Lower sides of leaves paler than the upper; leaflet-margins entire or obscurely serrate. _F. americana_, p. 213.

WINTER KEY TO THE SPECIES OF FRAXINUS

a. Twigs prominently 4-angled; fruit falling in early autumn.

_F. quadrangulata_, p. 219.

aa. Twigs terete; fruit often persistent on the tree until mid-winter or the following spring.

b. Buds rusty-tomentose; twigs more or less downy. _F.

pennsylvanica_, p. 215.

bb. Buds not tomentose; twigs not downy.

c. Terminal bud black or nearly so, showing 3 pairs of scales in cross-section; bud-scales apiculate at the apex; samaras with broad wings, the seed portion flattish; bark flaky, rubbing off on the hand. _F. nigra_, p. 221.

cc. Terminal bud brownish, showing 4 pairs of scales in cross-section; bud-scales rounded at the apex; samaras with narrow wings, the seed portion terete; bark ridged, not flaky and rubbing off on the hand.

d. Upper margin of leaf-scars deeply concave. _F. americana_, p. 213.

dd. Upper margin of leaf-scars not concave, but straight across or projecting upward. _F. pennsylvanica lanceolata_, p.

217.

[Ill.u.s.tration: +White Ash+

1. Winter twig, 1.

2. Leaf, 1/4.

3. Staminate flowering branchlet, 1/2.

4. Staminate flower, enlarged.

5. Pistillate flowering branchlet, 1/2.

6. Pistillate flower, enlarged.

7. Fruit, 1.]

+OLEACEAE+