Frost flowers are formed when the temperature of the air drops quickly while moisture is leaking out of the ground, or from vegetation, such as branches, tree bark, exposed roots, etc. The water is extruded as the temperature drops and freezes microscopically as it squeezed out. Conditions have to be just right; the water or sap source has to be moist while the air temperature drops to feezing. As in the case with these frost flowers, typically this can happen in late November. These delicate formations are found early in the morning before the sun strikes or in the shade, as these were. Phippsburg Maine November. For more on frost flowers see http://en.wikipedia.org/wiki/Frost_flower or here http://www.kuriositas.com/2012/12/frost-flowers-natures-exquisite-ice.html for some lovely images of frost flowers.