Transcript Dendrology - Delaware ENVIROTHON

2004 Envirothon Training
November 6, 2004
Blackbird State Forest
Trees You Should Know
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eastern white pine (Pinus strobus)
loblolly pine (Pinus taeda
Virginia pine (Pinus virginiana)
baldcypress (Taxodium distichum)
Atlantic white-cedar (Chamaecyparis
thyoides)
eastern redcedar (Juniperus
virginiana)
black walnut (Juglans nigra)
pignut hickory (Carya glabra)
river birch (Betula nigra)
American beech (Fagus grandifolia)
white oak (Quercus alba)
northern red oak (Quercus rubra)
southern red oak (Quercus falcata)
water oak (Quercus nigra)
willow oak (Quercus phellos)
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sweet bay (Magnolia virginiana)
yellow-poplar (Liriodendron
tulipifera)
sassafras (Sassafras albidum)
sycamore (Platanus occidentalis)
black Cherry (Prunus serotina)
black locust (Robinia pseudoacacia)
American holly (Ilex opaca)
red maple (Acer rubrum)
silver maple (Acer saccharinum)
devil’s club (Araila spinosa)
blackgum (Nyssa sylvatica)
flowering dogwood (Cornus florida)
persimmon (Diospyros virginiana)
green ash (Fraxinus pennsylvanica)
Common names are given to all plants and are
for the everyday person to use, they are easy to
pronounce and are usually descriptive. BUT:
• trying to communicate with someone from a
different region or country can be difficult.
• sometimes the same plant has many
different common names
• different plants may have the same common
name
• some plants are so rare that no common
name is given.
The Father of Botany
• Carl Linnaeus (1707-1778)
– was the first to consistently use a system of
binomial nomenclature which literally means
two names.
– Scientific names of plants consist of a generic
name and a specific epithet, in Latin either
underlined or in italics.
TAXONOMIC
CLASSIFICATION
King David
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Came Over For Good Spaghetti
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Delaware has over 60 species of
trees!
• It is hard to know every tree in the forest so
taxonomists have constructed dichotomous
keys to help identify them.
The Key to Knowledge
• Dichotomous Keys consist of a series of
two-way choices along the route from the
unknown to the known.
• At each fork in the road the user is asked a
pair of questions. Each question is designed
to divide a set of species into smaller groups
until there is only one left.
1.
2.
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a. wings covered by an exoskeleton……………….go to step 2
b. wings not covered by an exoskeleton………..….go to step 3
a. body has a round shape………………………….ladybug
b. body has an elongated shape…………………….grasshopper
a. wings point out from the side of the body………dragonfly
b. wings point to the posterior of the body………...housefly
Tree Keys
• Keying is a way to identify a plant or tree by
looking at the similarities and differences that
exist among them.
• A tree key would begin with a group of trees
that are split into two groups by comparing
different expressions of the same character
(flower color red or white).
• The first major separation would be whether or
not the tree is coniferous, bearing cones or
deciduous, sheds its leaves annually.
Keying takes practice
• Most tree keys use characters such as
leaf shape and seed descriptions to
create groups, the user must be familiar
with the terminology used to describe
these characters to be successful.
Basic Terminology
• Opposite: 2 or 3 leaves are directly across from each other on the
same twig
• Alternate: leaves that are staggered along stem
• Simple leaf: one leaflet, a petiole and a bud at its base
• Compound leaf: a single leaf that is made up of many leaflets Petiole:
the stalk of a leaf that connects it to the tree
• Needle-like: leaves long and narrow, thick in the shape of a needle
• Scale-like: leaves in the shape of small, flat thickened triangles that
hug the stem
• Entire: leaf edges is smooth no teeth or lobes
• Lobed: leaf has wavy edges
• Toothed: leaf has jagged edges
Usually the first question about the leaves will be their
arrangement: alternate, opposite, or whorled
Second division will be the leaf type: compound or simple.
Other characteristics to look for
when keying
• Texture of leaf or bark
• Smell or odor when leaf is crushed
• Hairs, glands, scales or lack thereof on bottom
of leaf
• Milky or clear sap when stem is pinched
• Habitat found growing
• Leaf surface shiny or dull