Laura Hlinka UMS 7th grade science Tree Identification Laura Hlinka UMS 7th grade science

Tree Identification Characteristics In order to correctly identify trees in nature it is important to know certain characteristics used in tree identification. Looking at characteristics other than leaves of a tree will help to identify it. This helps when there are no leaves on a tree or they are too high to see properly. These are just some of the techniques used in tree identification.

Tree Identification Characteristics Some of these characteristics that should be looked at when identifying a tree are: Leaf shape Twigs and buds Bud scars Fruit Flowers Bark Tree form/Branching pattern Where the tree is growing and what other plants and trees it may be growing around.

Leaves Leaves are NOT the best, but often the easiest way to identify a tree. Needles and scale of evergreens are also considered leaves. Questions to consider when identifying leaves: Are the leaves: simple or compound?  margins smooth or margins rough?  any sinuses or lobes? What is the size, shape, texture, and color variation of the leaves?

First question- Type of leaf Broad leaf Scale Needle - like

Evergreen Identification When identifying evergreens count the number of needles that occur in a group and then length of the needles. Needles that occur singularly may either be flat or round and have different numbers of white lines on the bottom of the needles. Needles that are flat may be all scale like as in cedar trees or junipers.

External Anatomy of a Leaf Margin Midrib Petiole Blade

External Anatomy of a Leaf

Leaves – Sinuses or Lobes A sinus is the indentation between two lobes. A lobe is a division of a leaf blade that is broadly attached.

Leaves – Simple or Compound Simple leaves only have one leaf blade.

Leaves – Simple or Compound Compound leaves are made up of several separate leaflets attached to a common leaf stem. Has only one petiole

Types of Compound Pinnately Compound Bipinnately Compound - Doubly compound Palmately Compound

Pinnately Compound More than one leaflet per petiole It kind of looks like a feather

Bipinnately Compound Doubly compound. Looks like a compound leaf on a compound leaf

Palmately Compound More than one leaflet per petiole, but they are attached like the fingers on your hand.

Leaves - Margins Margins are the edges of the leaves, which have different patterns. Examples of margins are: Smooth Serrate or Doubly serrate Dentate Crenate Undulate Sinuate Lobed

Entire = Smooth Edge of leaf is smooth No lobes or serrate

Serrate or Doubly serrate Edge of leaf is jagged all around.

Dentate Edge of leaf is deeply jagged like teeth

Lobed Edge of leaf is indented, but does not go all the way to the midrib

Leaves - Shapes Leaves can come in many shapes. Deltoid Lanceolate Elliptical Ovate Obovate Cordate

Leaf Shape Deltoid - triangular shaped

Leaf Shape Lanceolate Longer than wide

Leaf Shape Elliptical - tapers off at both ends

Leaf Shape Ovate - wider at base of leaf near petiole

Leaf Shape Obovate - wider at top of leaf

Leaf Shape Cordate - heart shaped leaf

Leaf Arrangements Leaf arrangement refers to the leaf arrangement on the stem of the tree. Leaves are arranged in three different ways: Opposite – Buds form in pairs on either side of the twig. Alternate – Buds are arranged singly at intervals along the twigs. Whorled – Buds are arranged in circles around the twig.

Leaf Arrangements OPPOSITE means the leaf petioles are attached oppositely of each other on the twig.

Leaf Arrangements ALTERNATE means the leaf petioles are attached in a staggered pattern, not OPPOSITE each other on the twig)

Venation Types - vein pattern of leaf

Scientific and Common Names Scientific names are used for standardization so everyone will know what tree is being discussed since common names change from one area to another. Scientific names are either italicized when typed or underlined when hand written. The genus of a scientific name is always capitalized and the species is always lowercase.

http://www.okplanttrees.org/okplantid/guides/leaves.html

http://www.arborday.org/trees/wtit/wtit.cfm