THE WOODSIAS

Small, tufted, pinnately divided ferns. Fruit-dots borne on the back of
simply forked, free veins. Indusium fixed beneath the sori, thin and often
evanescent, either small and open, or early bursting at the top into
irregular pieces or lobes. (Named for James Woods, an English botanist.)

(1) RUSTY WOODSIA. _Woódsia ilvénsis_

Fronds oblong-lanceolate, three to ten inches high, rather smooth above,
thickly clothed underneath with rusty, bristle-like chaff. Pinnate, the
pinnæ crowded, sessile, cut into oblong segments. Fruit-dots near the
margin often confluent at maturity. Indusium divided nearly in the center
into slender hairs which are curled over the sporangia. Stipes jointed an
inch or so above the rootstock.

[Illustration: Rusty Woodsia, _Woodsia ilvensis_]

The rusty Woodsia is decidedly a rock-loving fern, and often grows on
high cliffs exposed to the sun; its rootstock and fronds are covered with
silver-white, hair-like scales, especially underneath. These scales turn
brown in age, whence the name, rusty. As the short stipes separate at the
joints from the rootstock, they leave at the base a thick stubble, which
serves to identify the fern. Exposed rocks, Labrador to North Carolina and
westward. Rather common in New England. Said to be very abundant on the
trap rock hillocks about Little Falls, N.J., where it grows in dense tufts.

(2) NORTHERN WOODSIA. ALPINE WOODSIA