Cotton has been in the air for the past several weeks. Little pieces of white fluff floating to the ground. Where does it come from? The eastern cottonwood (
Populus deltoides) is your best guess. You can find this native tree all over town. It grows like a weed, popping up opportunistically in wet places. You might find one in a flower pot that you've been watering consistently. It's especially prolific along the banks of our Red River.
In the arboretum you can find one very large, although not very old, specimen. In April of 1998, this individual was collected from the
Walter B. Jacobs Memorial Nature Park, in Caddo Parish. Potted and then nurtured over the summer, it was planted later that year in November. It's located in a sunny spot on the west side of the arboretum, along a major drainage channel.
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| Our tree of the week is pictured center. This eastern cottonwood is a tall, straight tree, a little more than 20 years old. This species is known for its rapid growth. |
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| The eastern cottonwood grows near the northeast corner of Rotary Hall. Jackson Hall is pictured directly behind the cottonwood, further up the slope. |
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| This individual has developed impressive surface roots that make lawn maintenance more difficult. It's great for creating a 'natural setting,' but be wary of cottonwoods growing in areas that need to achieve that 'manicured look.' |
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| The roots stretch across the grass and then appear to dead-end at the sidewalk. |
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| These protruding roots inevitably sustain lawnmower damage. Do they also damage the lawnmower? Violence goes both ways. |
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| The undamaged surface roots have handsome, deeply furrowed bark. |
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| In the shade, the trunk bark is dark gray. |
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| With a little sun shining on the trunk, we see light gray furrows with dark ridges. |
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| A diamond pattern is visible on some portions of the trunk. Do these resemble the scales of some fantastic beast? |
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| During the past several weeks cotton has accumulated on the ground around the cottonwood. The edges of the sidewalk are lined with light-gray fluff. |
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| A few catkins were collected from the leaf litter for examination. Eastern cottonwoods are dioecious. This is a female catkin. It's mostly bare at this point. The white fluff is an open fruit. The fluff floats through the air or on water, disseminating the cottonwood seeds. There are two unopened fruit capsules still on the catkin. |
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| The fruits are small, measuring approximately ¼ inch. |
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| The female catkins measure approximately 5 inches in length. Some are straight, others curved. |
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| This is a female eastern cottonwood catkin with one open fruit remaining. |
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| This is a female eastern cottonwood catkin with several opened fruits. |
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| So much cotton! |
For more information about this species consult the following:
United States Department of Agriculture
Louisiana Plant Identification and Interactive Virtual Tours (LSU AgCenter)
US Forest Service
