Michigan Trees Part 33

+Mountain Ash+

_Pyrus americana (Marsh.) DC._ [_Sorbus americana Marsh._]

HABIT.--A small tree 15-20 feet high, with a trunk diameter of not over a foot; branches slender, spreading, forming a narrow, rounded crown.

LEAVES.--Alternate, compound, 6-9 inches long. Leaflets 9-17, 2-3 inches long and 1/2-3/4 inch broad; sessile or nearly so, except the terminal; lanceolate to oblong-lanceolate, taper-pointed; finely and sharply serrate above the entire base; membranaceous; glabrous, dark yellow-green above, paler beneath, turning clear yellow in autumn.

Petioles slender, grooved, enlarged at the base.

FLOWERS.--May-June, after the leaves; perfect; 1/8 inch across; borne on short, stout pedicels in many-flowered, flat cymes 3-5 inches across; calyx urn-shaped, 5-lobed, p.u.b.erulous; petals 5, white; stamens numerous; styles 2-3.

FRUIT.--October, but persistent on the tree throughout the winter; a berry-like pome, subglobose, 1/4 inch in diameter, bright red, with thin, acid flesh; eaten by birds in the absence of other food.

WINTER-BUDS.--Terminal bud about 1/2 inch long, ovoid, acute, with curved apex; lateral buds smaller, appressed; scales rounded on the back, purplish red, more or less pilose above, gummy.

BARK.--Twigs at first red-brown and hairy, becoming glabrous, dark brown; thin, light gray-brown on the trunk, smooth, or slightly roughened on old trees; inner bark fragrant.

WOOD.--Light, soft, close-grained, weak, pale brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Ludington and northward, princ.i.p.ally along the sh.o.r.e of L.

Michigan, but common throughout the Upper Peninsula.

HABITAT.--Prefers rich, moist soil on river-banks and on the borders of cold swamps; rocky hillsides and mountains.

NOTES.--More often a shrub. Easily transplanted, but slow of growth. One of the most beautiful trees of our northern forests.

[Ill.u.s.tration: +Serviceberry+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 1.

4. Flowering branchlet, 1/2.

5. Vertical section of flower, enlarged.

6. Fruiting branchlet, 1/2.]

+ROSACEAE+

+Serviceberry+

_Amelanchier canadensis (L.) Medic._

HABIT.--A small tree 25-40 feet in height, with a tall trunk 6-12 inches in diameter; forming a narrow, rounded crown of many small limbs and slender branchlets.

LEAVES.--Alternate, simple, 3-4 inches long and about one-half as broad; ovate to obovate; finely and sharply serrate; glabrous, dark green above, paler beneath; petioles slender, about 1 inch long.

FLOWERS.--April, when the leaves are about one-third grown; perfect; large, white, borne in drooping racemes 3-5 inches long; calyx 5-cleft, campanulate, villous on the inner surface; petals 5, strap-shaped, white, about 1 inch in length; stamens numerous; styles 5, united below.

FRUIT.--June-August; globular, berry-like pome, 1/3-1/2 inch long; turning from bright red to dark purple with slight bloom; sweet and edible when ripe.

WINTER-BUDS.--Yellow-brown, narrow-ovoid to conical, sharp-pointed, 1/4-1/2 inch long; bud-scales apiculate, slightly p.u.b.escent.

BARK.--Twigs smooth, light green, becoming red-brown; thin, pale red-brown on the trunk, smoothish or divided by shallow fissures into narrow, longitudinal, scaly ridges.

WOOD.--Heavy, very hard, strong, close-grained, dark red-brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Common throughout the state.

HABITAT.--Prefers rich soil of dry, upland woods and hillsides.

NOTES.--Hardy throughout the state. Grows in all soils and situations except in wet lands.

[Ill.u.s.tration: +Dotted Haw+

_Crataegus punctata Jacq._

1. Winter twig, 1.

2. Leaf, 1.

3. Flowering branchlet, 1/2.

4. Vertical section of flower, enlarged.

5. Fruit, 1.]

+ROSACEAE+

+The Haws, Thorns, Hawthorns or Thorn-apples+

_Crataegus L._

Owing to the complexity of the various forms in this group, the present state of uncertainty as to the value of certain characters, and the questionable validity of many of the a.s.signed names, it is thought to be beyond the scope of this bulletin to give more than a general description of the group as a whole, recommending the more ambitious student to the various manuals and botanical journals and papers for more detailed information.

The _Crataegi_ are generally low, wide-spreading trees or shrubs, with strong, tortuous branches and more or less zigzag branchlets usually armed with stiff, sharp thorns. The bark varies from dark red to gray and is shallowly fissured or scaly. The leaves are alternate, simple, generally serrate, often lobed, with short or long petioles. The flowers appear in May or June, with or after the leaves, in simple or compound corymbs, whitish or pinkish, perfect. The fruit is a red to yellow, sometimes blue or black pome, subglobose to pear-shaped, with usually dry and mealy flesh and 1-5 seeds. The winter-buds are small, nearly globose, l.u.s.trous brown. _Crataegus_ produces wood which is heavy, hard, tough, close-grained, red-brown, with thick, pale sapwood. The Haws are trees of the pasture-lands, the roadside, the open woods and the stream-banks, and are more common in the southern than in the northern portions of the state. Some of the species are desirable as ornaments in parks and gardens on account of their beautiful and abundant flowers and showy fruits.

+SUMMER KEY TO THE SPECIES OF PRUNUS+

a. Leaves oblong-ovate to obovate, abruptly ac.u.minate at the apex; marginal teeth not incurved.

b. Margin of leaves sharp-serrate with spreading teeth; leaves not rugose, the veins not prominent; fruit 1/4-1/2 inch long, bright red, racemose, July-August; bark of trunk brown, smooth or only slightly fissured; usually a large shrub. _P.

virginiana_, p. 157.

bb. Margin of leaves crenate-serrate; leaves more or less rugose, the veins prominent; fruit about 1 inch long orange-red, cl.u.s.tered, August-September; bark of trunk gray-brown, early splitting off in large, thick plates; a small tree. _P. nigra_, p. 161.

aa. Leaves oval to oblong-lanceolate, taper-pointed at the apex; marginal teeth incurved.