Thursday, November 1, 2012

Frost Flowers Bloom Along Bull Creek


Split epidermis of Verbesina virginica
We had our first frost flower "bloom" on Bull Creek last Saturday, October 27th.  It was ironic that it was the only day over several months that we had to be out of town and missed the excitement.  Fortunately frost flowers leave behind their incriminating evidence so we can tell that they were here.

The tell-tale long strips of split epidermis extended up to 18" high on the stalks of Verbesina virginica.  The temperature was forecast to be 28 degrees that night.  Deep in Bull Creek valley the sun only reaches the valley floor around 9 AM and it is shaded by 5:30 PM.  For this reason, it is almost always colder at night than the surrounding plateau.

Last year we had an unseasonally warm winter and the roots never froze.  We documented 40 mornings where there were frost flowers. (Yes, it is a little compulsive to keep track of each day's blooming but I didn't apparently have anything else to do at the time.)  The long term forecast is for another mild winter so I will start the count again.   I promise I won't blog about each one.

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