Types of Trees
There are two groups of trees, gymnosperms and angiosperms. All the trees throughout the world today are classified as either gymnosperms or angiosperms. The word Gymnosperm means "naked seeds". Gymnosperm seeds are visiable from the outside of the cone or fruit of the tree. No cutting or breaking is necessary to see the tree's seeds. The word Angiosperm means "hidden seeds". Angiosperm trees' seeds are hidden inside the cone or fruit and are not visible.
Some Examples:
Gymnosperm: Pines, spruces, larches, hemlocks, firs and cedars.
Angiosperms: Oaks, birches and palms.
This image is of acorns (seeds) from a Black Oak tree. The Black Oak along with other oak trees are classified as angiosperms because the seed is not visible from the outside. (Image 1.2)
This image is of an acorn opening. The seed developes a root system and a stem which break through the shell of the acorn. (Image 1.3)
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This image is of a Sitka Spruce cone and seeds. Sitka Spruce along with other species of spruce are classified as gymnosperms. (Image 1.4)
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Would a pear tree be classified as a gymnosperm or an angiosperm? and why?
Quick Question
Take some time to find either a gymnosperm or an angiosperm near your home. Take a photo and instagram the photo with the hashtag: #QuickQuest
Be sure to include the tree's classification!
Quick Quest
Gymnosperms and Angiosperms are not the only ways biologists have organized and group trees. Angiosperms trees are also catogorized or grouped as either being Monocots or Dicots. Monocots and dicots are the two smaller categories or groups which make up the larger angiosperm group. Again the distinction has to do with the appearance of the trees. Monocots have flower petals that occur in groups of four or five (or multiples of four or five). Dicot flower petals occur in groups of three (or mulitples of three). The two also differ in the how the vascular tissue (the small channels or veins that transport materials throughout the plant) appear. The vascular tissue in monocots appear as parallel veins on the leaves. The vasular tissue in dicots appear as branching veins on the leaves. If you were to take a cross section of the stem of a monocots leaf you would find that the vascular bundles are throughout the stem. In the case of dicots the vascular bundles are found on the outer edge of the stem. There is another different between the to groups. Monocots have one cotyledon and dicots have two cotyledons. The cotyuledon is the primary leaf of the embryo of a plant seed. (Image 2.0)
This image is a close up of a Bannana leaf. You can see that the vascular tissue (or veins) run parallel to eachother. This means that Bannana trees are monocots. (Image 2.1)
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This is an image of a maple leaf. You can see that the vasular tissue (or veins) branch off one another. This shows that maple trees are dicots. (Image 2.2)
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Cinema Central
Watch this video to learn even more about monocots and dicots!
Types of Trees Continued
2.0
Use the diagram to reforce what you have just read
Quick Question
If a tree had flowers that had 6 peddles each would that make the tree part of the monocots or part of the dicots group?
Quick Quest
Take a moment and go outside. Take a photo of a monocot or a dicot and upload the photo to instagram. Use the #QuickQuest. Be sure to include if the picture is of a monocot or a dicot and how you were able to identify it!