LEAVES.--Alternate, compound, 15-30 inches long. Leaflets 11-17, 2-4 inches long and one-half as broad; sessile, except the terminal; oblong-lanceolate; finely serrate; thin; yellow-green and rugose above, pale and soft-p.u.b.escent beneath. Petioles stout, hairy.

FLOWERS.--May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens 8-12, with brown anthers; the pistillate solitary or several on a common peduncle, about 1/3 inch long, their bracts and bractlets sticky-hairy; calyx 4-lobed, hairy; corolla 0; styles 2; stigmas 2, fringed, spreading, bright red.

FRUIT.--October; about 2-1/2 inches long, cylindrical, pointed, greenish, sticky-downy, solitary or borne in drooping cl.u.s.ters of 3-5; nuts with rough sh.e.l.ls, inclosing a sweet, but oily kernel; edible.

WINTER-BUDS.--Terminal bud 1/2-3/4 inch long, oblong-conical, obliquely blunt, somewhat flattened, brownish, p.u.b.escent.

BARK.--Twigs orange-brown or bright green, rusty-p.u.b.escent, becoming smooth and light gray; gray and smoothish on young trunks, becoming brown on old trunks, narrow-ridged, with wide furrows.

WOOD.--Light, soft, weak, coa.r.s.e-grained, light brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Of common occurrence in the southern half of the Lower Peninsula.

HABITAT.--Prefers low, rich woods; river-banks; low hillsides.

NOTES.--Leaves appear late and fall early. Pith chambered, chocolate-brown. Large trees usually unsound. Not easily transplanted.

[Ill.u.s.tration: +Black Walnut+

1. Winter twig, 1.

2. Leaf, 1/6.

3. Leaflet, 1/2.

4. Flowering branchlet, 1/2.

5. Staminate flower, back view, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, 1/2.]

+JUGLANDACEAE+

+Black Walnut+

_Juglans nigra L._

HABIT.--A large tree 60-80 feet high, with a ma.s.sive trunk 2-5 feet in diameter; forming an open, capacious crown of heavy branches and coa.r.s.e branchlets.

LEAVES.--Alternate, compound, 1-2 feet long. Leaflets 13-23, the terminal often lacking, 2-4 inches long and one-half as broad; sessile; ovate-lanceolate, taper-pointed; sharp-serrate; thin; yellow-green and glabrous above, lighter and soft-p.u.b.escent beneath. Petioles stout, p.u.b.escent. Foliage aromatic when bruised.

FLOWERS.--May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens numerous, with purple anthers; the pistillate solitary or several on a common peduncle, about 1/4 inch long, their bracts and bractlets hairy; calyx 4-lobed, p.u.b.escent; corolla 0; styles and stigmas 2.

FRUIT.--October; globose, 1-1/2-2 inches in diameter, smooth, not viscid; solitary or borne in cl.u.s.ters of 2-3; nuts with irregularly furrowed sh.e.l.l, inclosing a sweet, edible kernel.

WINTER-BUDS.--Terminal bud 1/3 inch long, ovoid, obliquely blunt, slightly flattened, silky-tomentose.

BARK.--Twigs brownish and hairy, becoming darker and smooth; thick, brownish or blackish on the trunk and deeply furrowed by broad, rounded ridges.

WOOD.--Heavy, hard, strong, close-grained, very durable in contact with the soil, rich dark brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Lower Peninsula as far north as Bay City, but more abundant in the southern portion of its range.

HABITAT.--Prefers rich bottom-lands and fertile hillsides.

NOTES.--Leaves appear late and fall early. Fruit very aromatic. Pith chambered, cream colored. The juices from the husk stain the hands brown. Not easily transplanted. Often infested with caterpillars.

+SUMMER KEY TO THE SPECIES OF CARYA+

a. Bark of trunk essentially smooth, not deeply furrowed nor s.h.a.ggy; husk of fruit less than 1/8 inch thick.

b. Leaflets usually 5-7, glabrous beneath; buds dome-shaped, greenish; kernel of nut sweet.

c. Twigs long-hairy; fruit less than 1 inch long. _C.

microcarpa_, p. 75.

cc. Twigs glabrous or nearly so; fruit 1-1/2-2 inches long.

_C. glabra_, p. 77.

bb. Leaflets usually 7-11, more or less downy beneath; buds elongated, bright yellow; kernel of nut bitter. _C.

cordiformis_, p. 79.

aa. Bark of trunk deeply furrowed or s.h.a.ggy; husk of fruit more than 1/8 inch thick.

b. Twigs more or less p.u.b.escent; leaflets 5-7, more or less p.u.b.escent beneath.

c. Twigs brownish; buds densely hairy; fruit 1-1/2-2 inches long. _C. alba_, p. 73.

cc. Twigs orange; buds merely p.u.b.erulous; fruit 1-3/4-2-1/2 inches long; (leaflets usually 7). _C. laciniosa_, p. 71.

bb. Twigs tending to be glabrous; leaflets usually 5, glabrous beneath. _C. ovata_, p. 69.

+WINTER KEY TO THE SPECIES OF CARYA+

a. Bark of trunk essentially smooth, not deeply furrowed nor s.h.a.ggy; husk of fruit less than 1/8 inch thick.

b. Terminal bud narrow, long-pointed, flattish, bright yellow; kernel of nut bitter. _C. cordiformis_, p. 79.

bb. Terminal bud broad, dome-shaped, not bright yellow; kernel of nut sweet.

c. Buds greenish; twigs glabrous; fruit 1-1/2-2 inches long.

_C. glabra_, p. 77.

cc. Buds red-brown; twigs long-hairy; fruit less than 1 inch long. _C. microcarpa_, p. 75.

aa. Bark of trunk deeply furrowed or s.h.a.ggy; husk of fruit more than 1/8 inch thick.