The largest subgroup of evergreen trees are conifers, which is Latin for “cone-bearer”. Not all evergreens are conifers, because in some climates (such as a tropical rainforest) plants like palm trees and shrubs shed and regrow leaves year-round. There are seven coniferous families, all of which have needle leaves and reproduce via cones.
When it’s time to reproduce, the male cones release millions of tiny grains of pollen, which the wind carries up toward the female cones. Coniferous trees can be self-pollinated to create genetically identical offspring, or the wind could carry pollen from one tree to another. After pollen is released, the male cones don’t have any further purpose so they fall off and die. In the image below, cloud of pollen grains are released by the male cones of an evergreen!
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Here are a few key differences:
- Spruce cones grow from the center of a stem. The overlapping scales are paper-like and thin.
- Pine cones also grow from a central stem. Some have spiny scales. The overlapping scales are woody and thick. Seeds are located at the scales’ base.
- Fir cones grow upwards from closer to the tip of the stem. Scales overlap and feel papery and flexible. They often fall apart while still connected to the tree.
- Hemlock cones are very small; only about one inch long. They grow from the tips of the branch and have thin, flexible scales.
For more information and helpful images, we recommend “Simple Keys for Identifying Conifers” by Playful Learning. Click here to visit their website!
References:
“Simple Keys for Identifying Conifers”. Playful Learning, playfullearning.net . Accessed on 12/6/17. https://home.playfullearning.net/resource/simple-keys-identifying-conifers-pine-family/
“Pollination by the Wind”. Newton’s Apple, newtonsapple.org.uk. Accessed on 12/7/17. http://www.newtonsapple.org.uk/pollination-by-the-wind/
Image Credits:
Hodan, George. “Evergreen”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net
Kratochvil, Petr. “Christmas Garland”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net
Moisset, Beatriz. “Pollen Flowing From a Pine Tree”. Released into the public domain under the Creative Commons Attribution-Share Alike 3.0 Unported license. Uploaded on 12/6/17 from commons.wikimedia.org
Kratochvil, Petr. “Cone and Needles Background”. Released into the public domain. Uploaded on 12/7/17 from publicdomainpictures.net