The Plants of Michigan Part 35

7a. Twigs brownish; buds densely hairy =Mocker-nut Hickory, Carya alba.=

7b. Twigs orange; buds very slightly hairy =King-nut Hickory, Carya laciniosa.=

BETULACEAE, the Birch Family

Trees or shrubs with alternate simple leaves and inconspicuous monoecious flowers, the staminate flowers in catkins, and the pistillate in catkins or small cl.u.s.ters.

1a. Trees, with white or yellowish bark exfoliating in thin papery plates or scales --2.

1b. Tree or shrub, with smooth, dark gray bark; trunk fluted with prominent longitudinal ridges =Hornbeam, Carpinus caroliniana.=

1c. Trees or shrubs; the bark more or less roughened, but not exfoliating; trunk not fluted --3.

2a. Bark white or chalky =Paper Birch, Betula alba var. papyrifera.=

2b. Bark yellowish =Yellow Birch, Betula lutea.=

3a. Shrubs, with leaves 4 cm. long or less --4.

3b. Shrubs or trees, with leaves 5 cm. long or more --5.

4a. Twigs glandular-warty =Dwarf Birch, Betula glandulosa.=

4b. Twigs not glandular =Swamp Birch, Betula pumila.=

5a. Twigs and bark with the odor of wintergreen =Sweet Birch, Betula lenta.=

5b. Twigs and bark without odor of wintergreen --6.

6a. Fruit cl.u.s.ters woody, persistent on the plant for a long time --7.

6b. Fruit cl.u.s.ters herbaceous, dropping in late autumn --9.

7a. Leaves rusty or whitish beneath, and p.u.b.escent at least on the veins =Speckled Alder, Alnus incana.=

7b. Leaves green beneath, and either p.u.b.escent or smooth --8.

8a. Leaves broadest at or below the middle =Mountain Alder, Alnus crispa.=

8b. Leaves broadest above the middle =Smooth Alder, Alnus rugosa.=

9a. Tree; fruit a cl.u.s.ter of bladder-like sacs each containing a small achene =Ironwood, Ostrya virginiana.=

9b. Shrubs; fruit a nut within a close-fitting involucre --10.

10a. Involucre of 2 broad bracts, almost separate and not much longer than the fruit =Hazel, Corylus americana.=

10b. Involucre of united bracts, prolonged into a bristly beak beyond the fruit =Beaked Hazel, Corylus rostrata.=

f.a.gACEAE, the Beech Family

Trees (or 1 species shrubby), with alternate simple leaves and monoecious flowers, the staminate flowers in catkins, and the pistillate solitary or in small cl.u.s.ters. Fruit a nut (or acorn) enclosed in a cup or bur.

1a. Leaves serrate with numerous sharp-pointed teeth --2.

1b. Leaves serrate, lobed, or entire, but never serrate with sharp-pointed teeth; fruit an acorn; pith 5-angled in the young twigs (Oak) --3.

2a. Bark gray, smooth; buds 3-4 times longer than wide; nut triangular =Beech, f.a.gus grandifolia.=

2b. Bark rough; buds relatively thicker; nut rounded =Chestnut, Castanea dentata.=

3a. Leaves entire, except for a bristle at the tip =s.h.i.+ngle Oak, Quercus imbricaria.=

3b. Leaves toothed or lobed, the points bristle-tipped --4.

3c. Leaves toothed or lobed, the points without bristles --10.

4a. Leaves entire below the middle, with a few shallow lobes beyond =Black Jack Oak, Quercus marilandica.=

4b. Leaves deeply lobed throughout --5.

5a. Cup of the acorn saucer-shape, covering less than one-third of the acorn --6.

5b. Cup of the acorn hemispherical or top-shape, covering one-third or more of the acorn --8.

6a. Length of the lateral leaf-lobes less than one-third the width of the leaf; acorn cup 2-2.5 cm. wide =Red Oak, Quercus rubra.=

6b. Length of the lateral leaf-lobes more than one-third the width of the leaf --7.

7a. Acorn depressed-globose, about 1 cm. in diameter =Pin Oak, Quercus pal.u.s.tris.=

7b. Acorn ovoid, 1.5-2 cm. thick =Schneck's Oak, Quercus schneckii.=

8a. Leaves p.u.b.escent beneath =Black Oak, Quercus velutina.=

8b. Leaves glabrous beneath --9.

9a. Buds glabrous; inner bark of the trunk yellow =Hill's Oak, Quercus ellipsoidalis.=

9b. Buds p.u.b.escent beyond the middle; inner bark of trunk red =Scarlet Oak, Quercus coccinea.=