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Ice Formations on Salvia and Vinca in Fall 2008
Dr. James R. Carter, Professor
Emeritus Geography-Geology Department Illinois State University, Normal
IL 61790-4400 |
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This page supplements the
discussion of ice formations with the diurnal freeze/thaw process. On this page I am showing images of
ice that grew on stems of Salvia and Vinca that grew in my yard in
2008. In 2007 my wife noted a patch of white in a flower bed and it
was ice on a dead stem of Salvia. So in summer 2008 we bought three
varieties of annual Salvia to enjoy the flowers and to see if they would
produce ice in late fall. We bought Red and Purple Salvia that
looked alike as plants and Victoria Blue Salvia,
that has a slightly different form. We put the plants in
different places and enjoyed their beauty during the summer.
Above is a collection of Red plants. An abundance of rabbits is the reason for the fence. By mid-November the red had faded and there was ice splitting the bark on the stem.
This is not a very exciting ice formation, but I am interested in learning why ice forms on a few selected species of plants. As such we need to learn on which plants it does form. I have looked at many plant stems and very few species have such ice. So, this image of ice is of value simply because it shows the stems of Salvia support the growth of ice. Below is a more dramatic
display of ice from a Red or Purple Salvia stem. Of course, this was
taken closer up.
This display of ice growing from the stem is similar to the displays of ice from some of the stems of White Crownbeard Verbesina virginica. Below is an attractive flower of ice growing out from the base of a stem of Salvia. I do not know if this was from the Red or Purple plants. In terms of plant form there seems to be no difference between the two. Likewise, the nature of the ice was similar between the two. In the ice flower above, note how the stem maintains its basic form and the super cooled water emerges between the thin slits in the stem to form ribbons of ice. Below is ice growing from a stem of Vinca. This is a very unique display. Sorry to say I do not have any photos of Vinca. I did not anticipate seeing ice on these stems so I did not focus on them when they were in bloom. This photo was taken in mid-November. The leaves of the Vinca have been zapped by the cold but the leaves of a neighboring plant appear to be healthy and green.
At the base of the Vinca stem below we find a flower of ice. This occurred 3 days later than the ice in the photo above. These show different stems of Vinca. The example of ice below is quite similar to that above. In both cases the size of the ice formation is 1-2 inches or 2-5 cm wide.
Now I know that Vinca supports the growth of ice and next year I will pay more attention to the plant. Also, note that you will not be able to see such ice formations if you cut off or pull the stems after the plants flowers. So, keep the plants in the ground and look for ice.
The Victoria Blue Salvia My wife and I liked the Blue Salvia and bought a couple of boxes of the plants. I put six in one large patch near some trees and put two in an open area at the SW corner of the house. These two had ground cloth around them and were covered over with large, round gravel.
Throughout November I had
ice on Red and Purple Salvia while the stems of White Crownbeard produced many interesting displays.
But nothing on the Victoria Blue Salvia. Then in December we had
snow that stayed around for many days. In late December we had very
warm temperatures and heavy rain that melted all of the snow. On
December 28 it was again below freezing and I found a little ice
on the stems of the plants that had it in
November. On that day I noticed
needles of ice in the soil, which crunched as I walked around the
yard. And, there was ice on the stems of the Blue Salvia. Why
now and not before? In many cases the ice
formations on the six stems were similar to that on the Red and
Purple Salvia. But, the example below shows the formations of
ribbons that are quite unique.
Note that on the left the ice splits the stem and while growing
along the stem.
Those two plants of
Victoria Blue Salvia that were planted at the SW corner of the house did
not grow very tall, probably in part because they needed more water in
that sunny area. But, when they finally
produced ice in late December they produced some small, intricate
formations of ice. The ribbons of ice below extending out from the
stem are so thin we can see through the ice to make out the rock
behind it. The total width of this display of ice in the photo is
about 2.4 inches or 6 cm.
I had trouble getting good positions to photograph these intricate displays of ice because the foliage got in the way. It was obvious the top of the stems would produce no ice so I cut off the stems about 3 inches / 7 cm above the ground. The two photos below were taken the next day showing ice on the cut-off stems. In the photo below the ice grew out from and curled around the stems. There appear to be three separate growths of ice, all with similar form. With no dead stems above I was able to get in a better position. These three pieces of ice measure about 2 inches or 5 cm across, in total.
Below we see a beautiful
flower of ice with four petals. This is perhaps 1.6 inches
or 4 cm across but it is well formed and clean. To the left is
a similar ribbon but not as well formed and to the back is the
familiar form of ice extending along the stem. These occurred
on December 30, 2008 -- a very attractive way to bring to close a
year of seeing ice in many forms.
But, the growth of ice on
plants continued into 2009. It was smaller but not worthy of web
space in my opinion. Then big snows fell and the ground froze. In late January and into February
there were periods of warmth where the ground thawed. Some days I
could see very small formations of ice at the base of plant stems.
These were not worthy of a photograph for there was little to be seen, but
the ice was there. The process of water moving up from the soil,
moving out from the stem and forming ice on the surface
continued. Return to the discussion
of the formation of ice with
the diurnal freeze/thaw process. Feel free to contact me at jrcarter@ilstu.edu if you see any ice of this nature in your early morning outings. |
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One of the many web pages of Dr. Jim Carter |
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