Fragile Fern

Cystopteris

Cystopteris bulbifera ( Bulblet Bladder Fern )
A fern, reaching up to 2 feet in height. It is native to moist woods in eastern North America ( from northeast South Dakota to northwest Minnesota to southern Quebec to Nova Scotia; south to eastern Oklahoma to central Alabama to far northern Georgia to central North Carolina ). In Ontario, it is found at least as far north as Lake Nipigon to Tobermory to Haliburton. It is endangered in South Dakota, Nebraska, Oklahoma, South Carolina, North Carolina and Maryland. It has always been rare in the region around Windsor, Ontario; except for the Lake Erie Islands where it was locally abundant before 1900.
The foliage is deep green.
Hardy zones 2 to 7 in shade on alkaline soil.

* photo taken by Patrick J. Alexander @ USDA-NRCS PLANTS Database

* photo taken by Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database

Cystopteris fragilis ( Northern Fragile Fern )
Also called Cystopteris tenuis. Similar to above but shorter. It is native to northeast North America ( from far northern Alaska to far northern Yukon to Great Slave Lake, N.W.T. to far northeast Alberta to The Pas, Manitoba to Lake Nipigon, Ontario to Petawawa to Gaspe and Newfoundland; south to eastern Oklahoma to central Ohio to western North Carolina to Maryland. Despite being locally abundant on Kelly Island and the Ohio shoreline; it has never been common in the Windsor-Detroit region. It has been reported from Jasper National Park and east of Calgary in Alberta.
Hardy zones 3 to 6.