Part 19

NOTES.--Slow of growth. Long-lived. Should be transplanted with ball of earth. Tolerant of varied soils and situations.

+SUMMER KEY TO THE SPECIES OF SALIX+

a. Leaf-petioles without glands.

b. Leaves 1/4-3/4 inch broad; petioles broad and flat. S. nigra, p. 37.

bb. Leaves 3/4-1/4 inches broad; petioles slender and terete. S. amygdaloides, p. 39.

aa. Leaf-petioles glandular above.

b. Leaves 1/4-1/2 inch broad, sharp-serrate; tree with weeping habit. S. babylonica, p. 43.

bb. Leaves 1/2-1-1/2 inches broad, blunt-serrate; tree with upright habit. S. fragilis, p. 41.

+WINTER KEY TO THE SPECIES OF SALIX+

The classification of the Willows is a task for the specialist, even when leaves and both staminate and pistillate flowers are obtainable. It is impractible for the novice to attempt the determination of species of Salix with winter characters alone. Consequently the usual winter key is omitted.

+SALICACEAE+

+Willow+

Salix (Tourn.) L.

The genus Salix is represented in Michigan by thirty or more distinct species, and there are many more hybrids. The majority of these are shrubs, only a few becoming truly arborescent. Because of the similarity of their botanical characters, the frequency with which they hybridize, and the facility with which they respond to their environment only an expert is competent to identify the species so abundant along our water courses and on the banks of our lakes and swamps. The scope of this work being necessarily limited, it has been deemed best to describe but two of our native willows and two of our foreign neighbors which are frequently planted.

1. Winter twig, × 1. 2. Portion of twig, enlarged. 3. Leaf, × 1. 4. Staminate flowering branchlet, × 1. 5. Staminate flower, enlarged. 6. Pistillate flowering branchlet, × 1. 7. Pistillate flower, enlarged. 8. Fruiting branchlet, × 1.]

+SALICACEAE+

+Black Willow+

Salix nigra Marsh.

HABIT.--A tree 30-50 feet high, with a short trunk, 1-2 feet in diameter; stout, spreading branches form a broad, rather irregular, open crown. Often a shrub.

LEAVES.--Alternate, simple, 3-6 inches long, 1/4-3/4 inch broad; lanceolate, very long-pointed, often curved at the tip; finely serrate; thin; bright green and rather lustrous above, paler and often hairy beneath; petioles very short, more or less pubescent.

FLOWERS.--April-May, with the leaves; dioecious; borne in crowded, slender, hairy catkins, 1-3 inches long; calyx 0; corolla 0; scales yellow, villous, stamens 3-6; ovary ovoid-conical, short-stalked, with stigmas nearly sessile.

FRUIT.--June; ovoid-conical capsule, 1/8 inch long, containing many minute seeds which are furnished with long, silky, white hairs.

WINTER-BUDS.--Terminal bud absent; lateral buds narrow-conical, acute, lustrous, red-brown, 1/8 inch long.

BARK.--Twigs glabrous or pubescent, bright red-brown, becoming darker with age; thick, dark brown or nearly black on old trunks, deeply divided into broad, flat ridges, often becoming shaggy.

WOOD.--Light, soft, weak, close-grained, light red-brown, with thin, whitish sapwood.

DISTRIBUTION.--Common throughout the state.

HABITAT.--Banks of streams and lake-shores.

NOTES.--Branchlets very brittle at the base, and these, broken off by the wind, are carried down stream, often catching in the muddy banks and there taking root.