How is some moss, lightly covered in frost last month, a sign that spring may be on the way? The clue is in the delicate-looking structures rising above the rest of the plant. They are setae (shoots). What looks like a blob of greenish fluid at their ends contains the spores, ready for being dispersed by the breeze.
The most common moss species in this area growing on the tops of walls (and elsewhere) sends out it setae early in the year.