. Bulletin (Pennsylvania Department of Forestry), no. 11. Forests and forestry. PLATE III. TYPES OF BUDS 1. Sugar Maple (opposite). 2. Chestnut (altemate), 3. Butternut (superposed). 4. Ked Maple (accessory). 5. Striped Maple (stalked). 6. Striped Maple (valvate). 7. Red Oak (scaly). 8. Buttonwood (sub-petiolar). 9. Beech (solitary terminal). 10. Black Oak (clustered and hairy terminal). 11. Basswood( axillary and psuedo-temiinal). 12. American Elm, showing (1) leaf buds and (f) flower buds. 13. Papaw (naked flower- and leaf-buds). 14. Common Locust (imbedded). 15. Trembling Aspen ((sharp-poin
. Bulletin (Pennsylvania Department of Forestry), no. 11. Forests and forestry. PLATE III. TYPES OF BUDS 1. Sugar Maple (opposite). 2. Chestnut (altemate), 3. Butternut (superposed). 4. Ked Maple (accessory). 5. Striped Maple (stalked). 6. Striped Maple (valvate). 7. Red Oak (scaly). 8. Buttonwood (sub-petiolar). 9. Beech (solitary terminal). 10. Black Oak (clustered and hairy terminal). 11. Basswood( axillary and psuedo-temiinal). 12. American Elm, showing (1) leaf buds and (f) flower buds. 13. Papaw (naked flower- and leaf-buds). 14. Common Locust (imbedded). 15. Trembling Aspen ((sharp-pointed). 43 warty or resinous exudations, corky projections, or decurrent pro- jections of the bark. If we examine a young twig just after it has emerged from the bud we will find that it is usually green in color. At the end of the first season^s growth a thick bark has usually developed which i« no longer green on the surface, but by cutting a cross section of a twig, one will often find that the inner bark is still green. This green tissue develops chlorophyll and manufac- tures food just as does the green tissue of the leaves. As the bark increases in thickness the chlorophyll decreases, eventually disap- pearing entirely from the stem. In order that this green tissue in the bark may function it is necessary that gases be exchanged through the bark. Special structural modifications on the bark known as lentlcels (Fig. 117 and 119) make possible this exchange of gases just as the stomata on the leaf-surfaces allow and even regulate the exchange of the gases of the leaf. The lenticels are very numerous and conspicuous on some trees while on others they are rare and inconspicuous. They are raised on some trees like the Elder, while on others they are even with the bank. Their color varies. They may be white, gray, pinkish, yel- low, brown, or black. In outline they are usually circular or slightly elongated. In the Cherries and Birches they are confluent, a char- acteristic whic
Size: 1293px × 1931px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectforests, bookyear1901
