Tree Identification

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 the best and 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?

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

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

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 - Shapes Leaves can come in many shapes. Some examples of leaf shapes are triangular, oval, or elliptical.

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 Most trees have alternate branching.

Twigs and Buds A twig is the current year’s growth on a tree. A bud is where the leaves will eventually grow from and is located on a twig. Buds can be pointy, blunt, shiny, dull, smooth, hairy, and come in many colors. A bud scar is where last year’s leaves fell off. Bud scars are unique for every species.

Twigs and Buds Terminal buds are on the end of a twig. The marks inside a leaf scar are called bundle scars.

Fruit and Flowers Fruit is the matured ovary of a flowering plant – the seed bearing product of the plant. In conifers the fruit is called a cone. Select fruit types: Drupe Berry Acorn Samara Pome Legume It is easier to identify a tree by its fruit because it is on the tree longer than flowers.

Bark Bark is a helpful for identification in the fall and winter when leaves are not available. Bark is the outer layer of the tree that covers the inner layers of the tree that move nutrients upward to the foliage. Main bark characteristics are thickness, degree of roughness (smooth, scaly, furrowed), color of outer and inner bark, depth and breadth of fissures, width of fissures, and length of plates.

Tree Forms A tree form is basically the silhouette that a tree makes. It is the general overall shape of a tree. Trees of the same species will not all have the same silhouette. Tree forms differ by the tree specie, age of tree, whether it is in an open or forested area. When using tree forms for identification do not use trees in a forested area because they may not have had optimal growth due to light and water requirements.

Tree Forms Some examples of tree forms are: Conical (Balsam Fir) Pyramidal (White Spruce) Slender (Black Spruce) Vase-shaped (American Elm) Oblong (Shagbark Hickory) Drooping (Weeping Willow)

Angiosperms vs. Gymnosperms Angiosperm – A flowering plant. Gymnosperm – young seeds naked at the time of pollination, the mature seeds never borne in an ovary or fruit. Angiosperms are also considered flowering plants. These trees lose their leaves in the winter with the exception of evergreen angiosperms. The major group of gymnosperms in Michigan are conifers and the major group of angiosperms are the broad leafed trees.

Evergreen Identification Evergreens or conifers are identified differently than deciduous trees. In evergreens needles or scales do not fall off in the winter except in a few species like the tamarack. Conifers have either needles like a white pine or scales like a cedar. Cone shape, size, and color can also be used in evergreen identification.

Evergreen Identification Needles occur in three ways on evergreens: Needles grow in clusters of two or more (ex. true pines). Needles grow in clusters of 10 or more in short lateral shoots (ex. Tamarack). Needles grow solitary along the branch (ex. spruce).

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. Evergreen Identification