Guttation

This plant is showing guttation. Water gets forced through the plant and exudes as drops at the edge of the leaf where there are special leaf structures called hydathodes.  This plant is a Geum, possibly Geum canadense.  Rose family plants like Geums and roses and strawberries often exhibit guttation.

Link to guttation:

Link to hydathodes:

Link to Geum canadense:

This spiderwort also has droplets of fluid at the edge of its leaves caused by guttation.

Pictures taken May 24, 2011, at Celery Bog Park, on a humid morning.