Part 6 (1/2)

2. Leaf, 1/2.

3. Staminate flowering branchlet, 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, 1.]

+GINKGOACEAE+

+Ginkgo.[C] Maidenhair Tree+

_Ginkgo biloba L._ [_Salisburia adiantifolia Smith_]

HABIT.--A slender tree in youth, with slender, upright branches, becoming broader with age and forming a symmetrical, pyramidal crown; probably 60-80 feet high, with a trunk diameter of 2-4 feet.

LEAVES.--Cl.u.s.tered at the ends of short, spur-like shoots, or scattered alternately on the long terminal branches; simple; 2-5 inches broad; more or less fan-shaped; usually bilobed and irregularly crenate at the upper extremity; thin and leathery; glabrous, pale yellow-green on both sides; petioles long, slender; turning a clear, golden yellow before falling in autumn.

FLOWERS.--May, with the leaves; dioecious; the staminate in short-stalked, pendulous catkins, 1 to 1-1/2 inches long, yellow; the pistillate more or less erect on the shoot, long-stalked, consisting of 2 naked ovules, one of which usually aborts.

FRUIT.--Autumn; a more or less globose drupe, orange-yellow to green, about 1 inch in diameter, consisting of an acrid, foul-smelling pulp inclosing a smooth, whitish, somewhat flattened, almond-flavored nut.

WINTER-BUDS.--Terminal bud about 1/8 inch long, conical, smooth, light chestnut-brown; lateral buds divergent, usually only on rapid-growing shoots.

BARK.--Twigs gray-brown and smooth; thick, ash-gray and somewhat roughened on the trunk, becoming more or less fissured in old age.

WOOD.--Light, soft, weak, close-grained, yellow-white to light red-brown, with thin, lighter colored sapwood.

NOTES.--Origin in dispute, but probably a native of northern China.

Extensively cultivated in China and j.a.pan, where its fruit is esteemed.

Easily propagated from seed. Thrives in deep, well-drained, rich soil.

Practically free from insect and fungous attacks, and little harmed by the smoke of cities. Probably hardy throughout the southern half of the Lower Peninsula.

+SUMMER KEY TO THE SPECIES OF PINUS+

a. Leaves 5 in a cl.u.s.ter; cones 4-10 inches long. _P.

strobus_, p. 7.

aa. Leaves 2 in a cl.u.s.ter; cones less than 4 inches long.

b. Leaves 1-3 inches long.

c. Leaves about 1 inch long, divergent; cones sessile, pointing forward towards the tip of the branch, persistent 10-15 years, opening very unevenly. _P. banksiana_, p. 9.

cc. Leaves 1-1/2-3 inches long, slightly divergent; cones stout-stalked, pointing away from the tip of the branch, maturing in second season, opening evenly. _P. sylvestris_, p.

13.

bb. Leaves 3-6 inches long.