by Bob Harms ()

Last Crystallofolia by Verbesina virginica, March 8, 2008

On March 8, at 25° F, V. virginica once more produced crystallofolia. All plants had previously lost their epidermis down to the very base. Less than c. 1% of stems displayed ice crystals and, as in late February, no Pluchea odorata. The amount of ice was even less than on Feb. 27, and would probably not have been noticed had I not gone looking for it. Only one plants exhibited clearly defined fibrous ribbons (above left).

As earlier, the only apparent source of pressure was root pressure, perhaps drawing water as the result of evaporation at the surface of the exposed xylem rays. There was a continued reduction in quantity of ice in spite of recent rains and soil moisture. Green shoots for the coming season continued to grow, as may be seen in the photo above right, for the two larger plants shown on other pages.

A selection of pictures from March 8 (click to enlarge — on the enlargements note the frost which has formed on surrounding objects):

Plum flower with abundant frost condensation, March 8.