Page:Parsons How to Know the Ferns 7th ed.djvu/234

 delight in this new promise we forget for a moment to mourn the vanishing summer.

The outline of the Common Bladder Fern suggests that of the Obtuse Woodsia. The two plants might be difficult to distinguish were it not for the difference in their indusia. At maturity the indusium of the Common Bladder Fern usually disappears, leaving the fruit-dot naked, while that of the Obtuse Woodsia is fastened underneath the fruit-dot and splits apart into jagged, spreading lobes.

The sterile fronds of the Slender Cliff Brake also have been thought to resemble this fern, in whose company it often grows.

Williamson says that the Common Bladder Fern is easily cultivated either in mounds or on rockwork.

From Labrador and Greenland south to North Carolina and Kentucky, usually on exposed rocks in somewhat mountainous regions. A few inches to nearly one foot high.

Fronds.—Oblong-lance-shaped, rather smooth above, the stalk and under surface of the frond thickly clothed with rusty chaff, once-pinnate; pinnæ oblong, obtuse, sessile, cut into oblong segments; fruit-dots round, near the margin, often confluent at maturity; indusium detached by its base under the sporangia, dividing into slender hairs which curl above them.}}

Last Decoration Day, while clambering over some rocky cliffs in the Berkshire Hills, I found the Rusty Woodsia growing in masses so luxuriant to the eye and so velvety to the touch that it hardly