Part 48

+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 assigned 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, lustrous 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 acuminate 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, clustered, 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.

b. Fruit light red, clustered, July-August; twigs usually less than 1/16 inch thick; pith of twigs brown; tree northern. P. pennsylvanica, p. 139.

bb. Fruit black, racemose, August-September; twigs usually more than 1/16 inch thick; pith of twigs white; tree southern. P. serotina, p. 155.

+WINTER KEY TO THE SPECIES OF PRUNUS+

a. Terminal bud present; bark of young trunks rather smooth.

b. Buds clustered at the tips of all shoots; twigs usually less than 1/16 inch thick; pith of twigs brown. P. pennsylvanica, p. 159.

bb. Buds not clustered, or clustered only on short, spur-like branchlets; twigs usually more than 1/16 inch thick; pith of twigs white.

c. Buds usually 1/4 inch or less in length; bud-scales uniform in color, apiculate at the apex; bark on old trunks blackish, rough-scaly; small to large tree. P. serotina, p. 155.

cc. Buds usually 1/4-1/2 inch long; bud-scales grayish on the margins, rounded at the apex; bark on old trunks brown, smooth or only slightly fissured; usually a large shrub. P. virginiana, p. 157.

aa. Terminal bud absent; bark of young trunks early splitting off in large, thick plates. P. nigra, p. 161.

1. Winter twig, × 1. 2. Portion of twig, enlarged. 3. Leaf, × 3/4. 4. Margin of leaf, enlarged. 5. Flowering branchlet, × 1/2. 6. Vertical section of flower, enlarged. 7. Fruiting branchlet, × 1/2.]

+ROSACEAE+

+Black Cherry+

Prunus serotina Ehrh. [Padus serotina (Ehrh.) Agardh.]

HABIT.--A medium-sized tree 40-50 feet high and 8-36 inches in trunk diameter; branches few, large, tortuous, forming a rather spreading, oblong or rounded crown.

LEAVES.--Alternate, simple, 2-5 inches long, about one-half as broad; oval or oblong to oblong-lanceolate; finely serrate, with teeth incurved; subcoriaceous; dark green and very lustrous above, paler beneath, glabrous both sides; petioles short, slender, usually bearing 2 red glands near the blade.

FLOWERS.--May-June, when the leaves are half grown; perfect; 1/4 inch across; borne on slender pedicels in many-flowered, loose racemes 4-5 inches long; calyx cup-shaped, 5-lobed; petals 5, white; stamens 15-20; stigma thick, club-shaped.

FRUIT.--August-September; a globular drupe, 1/3-1/2 inch in diameter, nearly black, with dark purple, juicy flesh; slightly bitter, edible.

WINTER-BUDS.--Terminal bud about 1/4 inch long, ovoid, blunt to acute; scales keeled on the back, apiculate, light brown.