Other Activities

  1. Inventory all die trees on your campus. Present the data as a map, brochure, or interactive database accessible on a Web Site. This could be useful for other students, alumni, community members, landscape staff, and long-range planners.
  2. Identify the wood used to produce specific picccs of furniture or other wooden objects. Relate the wood to its practical application or beauty.
  3. Use tree-ring analysis to date wooden objects from an archacological site or historical dwelling.
  4. Use rounds cut out of a tree to reconstruct the tree in the lab.
  5. Carefully examine a knot in a piccc of wood. Use eolored clav to reconstruct a model to show how the tree grows new tissue around a branch or wound.

NAME DATE

LAB SECTION NUMBER

WORKSHEET 15-1 EXERCISE C: TWIG MORPHOLOGY

  1. Write a description of one of your twigs in as much detail as possible.
  2. Critique of above description.

Classmate's name

NAME DATE

LAB SECTION NUMBER

WORKSHEET 15-2 EXERCISE C: TWIG MORPHOLOGY

Use your cwig specimens to locate and label all the structures on this diagram.

FIGURE I 5.9 MORPHOLOGY OF A TWIG IN WINTER.

Labeled Honey Locust Twig

FIGURE I 5.9 MORPHOLOGY OF A TWIG IN WINTER.

How is your specimen different from this diagram?

TABLE 15.1 WINTER KEY TO SOME COMMON TREES

  1. Evergreen tree producing seeds in cones; narrow, needle-shaped leaves^ — _ ~ —.— —___2
  2. Deciduous tree that loses its leaves in autumn or evergreen tree with broad leaves, seeds produced in fruits from flowers 24
  3. Seeds produced in a cone that appears'berrylike." either red. blue, or black -..3
  4. Seeds produced in a woody cone 4
  5. Seeds surrounded by a scarlet aril. I cm in lengrh (appears like a berry); (eaves about 3 cm long, narrow, and flattened; bark dark, thin, and scaly Taxus spp (Yew)
  6. Seeds within a small (5 to 20 mm) fleshy cone.starting pale green and turning blue or black, with frosty appearance to surface; leaves very tiny, scalelike, and overlapping on branches; aromatic - Junipervs spp. (Juniper)
  7. Cones with scales that overlap like shingles - 5
  8. Cones whose scales, with the exception of the broad flattened tips, do not overlap like shingles 21
  9. Leaves scalelike, very small, and overlapping; branches in flattened sprays— - Thuja spp. (Arborvitae)
  10. Leaves narrow and more or less flattened, or needlelike 6
  11. Leaves narrow and flattened 7
  12. Leaves needlelike, often in clusters of 2 or more - 11
  13. Cones bome erect on branches, falling apart at maturity leaving the central stalk of the cone erect; thin woody bracts not present between cone scales; tips of flattened leaves often rounded or shallowly notched (friendly to a hand grasp).,— ~ — ~ Abies spp. (Fir)
  14. Cones hanging down from branches, falling from tree intact; thin woody bracts present between the cone scales.— 8
  15. Cones usually less than 2 cm ¡ong: leaves appearing two-

Tsuga spp. (Hemlock)

  1. Cones usually greater than 2 cm long; leaves arranged spi rally around the twig
  2. Leaves definitely flattened with rounded tips (friendly to a hand grasp); buds pointed; cone bracts longer than the scales and with three prominent lobes, appearing forked Pseudotsuga menziesü (Douglas fir)
  3. Leaves stiff and 4-angIed to somewhat flattened, sharp-pointed (unfriendly to a hand grasp); buds rounded; cone bracts shorter than scales...

15. Cones 7-9 cm long; leaves spine-tipped, sharp, extending at right angles to the branch, when chewed have a sharp, acid, pungent taste; twigs smooth; branch arrangement of mature trees gives crown a layered appearance P/ceo pungens (Colorado blue spruce)

Cones about 5 cm long; leaves acute to blunt, usually pointing forward on stem: lacking sharp acid taste: twigs more or less pubescent: crown not layered ficca cngcirrrann.i (Engelmann spruce)

Leaves in tight spirals toward ups of short, spurlike branches; leaves deciduous in winter Lcnx spp. (Larch)

Leaves in clusters, usually 2-5 needles per cluster _...I2

Leaves in clusters of 2-3__________________________________________13

Leaves in clusters of 5____________________.____________________17

Leaves mostly in clusters of only 2 «rarely 3). Leaves mostly in clusters of 3 - _

Two needles in a cluster, each needle less than 7.5 cm long, yellow green to green, often twisted; cones 3-5 cm long, often remaining closed for many years, open with heat of fire or gap opening in forest, common in western U.S —Pinus contortc (Lodgepole pine)

  1. Two needles in a cluster, each needle 8-14 cm long, common m eastern U.S.. especially the upland soils of southern Appalachian Mountains________Pinus cchinota (Shortleaf pine)
  2. Needles 7-12 long, three needles in a cluster: mostly native to Atlantic coastal sutes and

New England Jmus ngida (Pitch pine)

  1. Needles 12-45 cm long______________________________________16
  2. Three needles in a cluster, each 12-30 cm long, yellow-green to gray-green: cones 10 cm long, open and deciduous when mature; common in western U. S Pmus ponderosa (Ponderosa pine)
  3. Three needles in a cluster, each 20 45 cm long, bnght green, densely tufted, at ends of stout branch tjps. common in southern U. S P¡nus palustris (Longleaf pine)
  4. Cones with long stalk: cone scales thin; seeds with wing longer than seed itself_____________________________________________18
  5. Cones with short stalk; cone scales thick: seeds with wing shorter than seed or lacking _ 20
  6. Needles straight, slender, and flexible. 5-13 cm long, dark bluish-green 19

18 Needles often twisted, relatively stiff: cones 40 cm long on long stalk: common in west slopes of Sierra Nevada Pinus iembervana (Sugar pine)

  1. Cones 12 cm long: common in eastern U. S.; needles 8-13 cm long _ Pmus strobus (Eastern white pine)
  2. Cones 20 cm long; common in western U. S.; needles 5-10 cm...----- -----------J^nus monvcola (Western white pine)
  3. Cone cylindrical, about 12 cm long, opening at maturity: seeds with a very short terminal wing (sometimes wingless) _ — — — Pinus flexilis (Limber pine)

TA B L E 15.1 WINTER KEY TO SOME COMMON TREES (continued/

20. Cone ovoid, about 6 cm long, remaining closed at maturity; seeds wingless fmus dbkaulis (Whitebark pine)

21 Center of scale tips depressed —22

22 Leaves narrow and flattened: cones

1-2.5 cm long Scguoio semperwrens (Coastal redwood)

22. Leaves small, short, and pointed: cones

5-10 cm long Seouoiodendron gigontcum (Sequoia)

23. Center of scale tip ending in a sharp point; cones about 1-2 cm in diameter;

foliage gray-green--------------Ccvpressus macnabiana (Cypress)

23 Center of scale tip not sharply pointed; cones about 0.75 cm in diameter Qiamaccyporis tawsoniona (Port Orford cedar)

24 Deciduous tree; leaf scars alternate or in a spiral 25

24 Deciduous tree; leaf scars opposite or whorled 47

25 Vascular bundle scars. 3 or more in a V-shaped or crescent-shaped line — - -.26

25. Vascular bundle scar. I (or seemingly I), arranged in a circle or irregularly scattered —_________________________41

26 Stipules or stipule scars present — — 27

  1. Stipules or stipule scars absent...,________________________________34
  2. Terminal bud present 28
  3. Terminal bud absent „ _ _ 29
  4. Pith circular in outline; bud scales sticky; buds not stalked Populus spp. (Cottonwood)
  5. Pith triangular in outline: bud scales with feltlike surface, buds on short stalks: conelike inflorescence of female flowers. often in clusters Alnus spp. (Alder)
  6. Leaf scar does not completely surround axillary bud 30
  7. Leaf scar completely surrounds axillary bud— — _ - flatanus spp. (Sycamore)
  8. Single hoodlike scale covering each bud.—Sofcr spp (Willow)
  9. Several overlapping scales covering each bud- 31
  10. Older bark of tree peeling in thin, papery sheets; lenticels forming horizontal lines..__________Beiulo spp. (Birch)
  11. Bark not in paper-thin sheets or lenticels not in horizontal
  12. Buds asymmetrical in appearance; bud scalcs usually red, occasionally greenish Tito spp. (Basswood, Linden)
  13. Buds symmetrical in appearance: bud scales brown 33
  14. Tips of buds flattened; pith of internode appears chambered in longitudinal cut: bark of tree trunk and older branches with raised, vertical, corky ridges _ Celtis occidental* (Hackberry)
  15. Tips of buds not flattened: pith solid; bark usually without raised corky ridges —-----------------------Ulrnus spp. (Elm)
  16. Terminal bud present___________________________________________~35
  17. Terminal bud absent J 7
  18. When twigs cut lengthwise, pith is chambered; buds stain fingers when crushed Jugbns ntgro (Black walnut)
  19. Pith not chambered 36
  20. 3ranches often with corky ridges of bark; bud scales with tiny hairs along margin; fruit a persistent globose head of beaked capsulcs Lquidombar styrvafluo (Sweet gum)
  21. Branches without corky ridges: twigs often with obvious lenticels. usually bitter to taste: bud scales without tiny hairs along margin— —.Pnjnus spp. (Cherry and Plum)
  22. Vascular bundle scars in sets of 3— — 38
  23. Vascular bundle scars. 5 or more— 39
  24. Twigs angular in cross section; stipular spines often present— Robinio pseudoocacio (Black locust)
  25. Twigs more or less round in cross section; stipular spines absent, in older trees or trees in the wild large branched spines are often present on the trunk (the branched spines are seldomfound on cultivated trees 40 years old or less) Oeditisa thaconlhos (Honey locust)
  26. Leaf scar V-shaped, partly surrounding the axillary bud _ —Rhus spp. (Sumac)
  27. Leaf scar semicircular or triangular.______________________________40
  28. Pith yellowish-tan; twigs foul-smelling when bruised Arfonthus atnssima (Tree of heaven)
  29. Pith pink to salmon: twigs not foul-smellmg when bruised

— Gymnodadus dhka (Kentucky coffeetree)

  1. Vascular bundle scar. I or seemingly I 42
  2. Vascular bundle scars. 4 to many, arranged in a circle or irregularly scattered — 43
  3. Terminal bud absent; twigs gray, not aromatic when bruised — -Diospyws spp. (Persimmon)
  4. Terminal bud present: twigs green, aromatic when bruised Sassafras spp. (Sassafras)
  5. Terminal bud present— 44
  6. Terminal bud absent - — 46
  7. Stipule scars barely extending back from upper corners of leaf scars----------------------------------------Quercus spp. (Oak)
  8. Stipule scars partially or completely encircling twig -45

45 Bud scales, several, overlapping: buds long-pointed- — Fogus spp. (Beech)

45. Bud scales, 2. forming a hood over bud; leaf scars circular—Uriodcndrorf tul/pifero (Yellow poplar. Tulip tree)

TABLE 15.1 WINTER KEY TO SOME COMMON TREES (continued)

  1. Visible bud scales. 4 or more — Morus spp. (Mulberry)
  2. Visible bud scales. 2 or 3: buds and twigs reddish, occasionally greenish; twigs zigzag in appearance Tilia spp. (Basswood, Linden)
  3. Leaf scars whorled. mostly in 3s— Ccialpc spp. (Cacalpa)
  4. Leaf scars opposite — — - 48
  5. Vascular bundle scars small and numerous, forming U-shaped lines — — —Fraxmus spp. (Ash)
  6. Vascular bundle scars distinct and separate.- - 49
  7. Vascular bundle scars. 3____________________________________________50
  8. Vascular bundle scars. 5 or more « 51
  9. Terminal buds large and conspicuous: axillary buds tiny and barely visible to unaided eye.— „Cornus spp (Dogwood)
  10. Terminal buds slightly larger than the easily seen axillary buds ~.Accr spp. (Maple)
  11. Terminal bud absent: spongy pith occupying at least 'A of the diameter of the rwig._ Sombucus spp. (Elderberry)
  12. Terminal bud present: pith small; stout twigs.

large leaf scar with vascular bundle scars in V-shaped pattern Aesculus spp. (Buckeye, Horse chestnut)

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  • HABEN ELIAS
    How to label a twig from winter from a tree?
    8 years ago

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