Rootstock: short. Leaves: thin, oblong-lanceolate, slightly tapering below; pinnae irregularly pinnatifid, with a broad central space and toothed segments decurrent along the margined or winged rachis, without bulblets.

A delicate, wet-loving fern, which uncurls early in the spring, and soon dies away. It receives its distinguishing name from the stalks, which are slender and very brittle.

Cystopteris montcma, or Mountain Bladder Fern, has a slender, widely creeping root, and leaves which are deeply toothed.

Plate II

Spinulose Shield Fern (Aspidium spinulosum var. dilatatum)