Saturday, December 5, 2009

Blooming in December

The morning after the temperature dropped to 10 degrees on Bull Creek, the edges of the field and roads blossomed with white flowers.  Well, sort of flowers.  Frost flowers are ribbons of ice which split the stems of three types of Missouri wildflowers as the sap freezes.  The spirals may extend more than eight inches up the stem or curl around the base in complex rosettes up to 8" in diameter.  The individual ribbons are so thin that you can see your fingerprint through them.
Our frost flowers form on the stems of White crownbeard (Verbesina virginica), also known as Frostweed.  They can also be found on Yellow Ironweed (Verbesina alternifolia), Hoary Frostweed (Helianthemum bickmellii) and Dittany (Cunila origanoides).

Frost flowers typically are seen with the first hard freeze but may reappear with the second or third freeze as well, typically with smaller displays of ribbons.  Technically they should be called Ice Flowers as they are formed from freezing water rather than freezing water vapor which forms frost.  (For more on this, check out this link
 Some of the our frost flowers from Bull Mills as well as their parent wildflowers can be seen by clicking on this from Missouri Conservationist.