Smooth woodsia, Woodsia glabella.

The glabrous (or smooth) undersurface of the leaves of this fern inspired the second word in its scientific name, Woodsia glabella. Accordingly, the plant is commonly called smooth woodsia. The clear balls that are visible here under the simple leaflets are called sporangia. They contain the spores that will eventually form new fern plants. Between them are narrow hairs that are one-row-of-cells wide.