Saturday, May 28, 2011

A Few Indiana Ferns, Part 3

The strange little ferns shown below are members of Ophioglossaceae, the Adder's Tongue Fern family. Many are highly variable and subject to much disagreement in nomenclature and identification.

Botrychium simplex?, Least Grape Fern
This very tiny fern was growing in thin woods along the edge of an open marsh. It is possibly Botrychium simplex, or conceivably could be a diminutive B. matricariaefolium (see below). Both species are highly variable. I am led to call it B. simplex mainly because of the absence of a midrib on the pinnae (lateral lobes of the blade).

Botrychium matricariaefolium, Daisyleaf Grape Fern

The specific epithet is also spelled matricariifolium. This curious little fern seems to be expanding its range in recent years. Once rare, it is becoming somewhat frequent in wooded areas. It has a special affinity for young Red Maple thickets that develop in formerly open areas. Its morphology is outlandishly variable.

Botrychium virginianum, Rattlesnake Fern
This is one of the few Botrychium ferns that is easy to identify. It's leaves are thin where most other Botrychiums are thick and leathery. It's blade is always triangular in outline, and it is much larger than the other Botrychiums. It is common in a variety of quality woodlands and even degraded woodlands. The reason for the common name is unclear.

Botrychium dissectum var. obliquum?, Oblique Grape Fern
This fern is somewhat common in northern Indiana, emerging in late summer or fall and persisting through the winter. Botrychium dissectum and its varieties are extremely variable; their nomenclature is caught in a never ending flux. I would be very surprised to find 3 or 4 authors who treat them the same, hence the question mark.

Ophioglossum vulgatum, Southern Adder's Tongue Fern
This small fern was photographed in deep shade in a hilly forest between the Salamonie and Wabash Rivers in central Indiana. The colony was discovered by Scott Namestnik.

Ophioglossum pusillum, Northern Adder's Tongue Fern
This inconspicuous little plant is somewhat easy to find in quality wet prairie remnants. It has a special affinity for the shade beneath large masses of Cinnamon Fern and Royal Fern in wet sand prairie. It is worth noting that it was an associate of the remarkable Thismia americana on the south side of Chicago.


The Phytophactor said...

What a great array of terrific little ferns! Never seen B. simplex myself.

Scott Namestnik said...

Wow... after seeing your photo of B. simplex, for the first time I understand why the Botrychiums are called "grape ferns." Nice post!

Plumes de terre said...

Adder's Tongue is amazing. Never seen then up here in the north. Couldn't believe it's even a fern.

Ferns, the feathers that have fallen onto the earth

Anonymous said...

Pretty sure your "B. simplex" photo is actually a small B. matricariifolium. The latter almost always has a red stem and small/underdeveloped specimens won't have a raised midrib, and B. simplex does not have a redish stem, they are always green to lime green to white(though you probably won't find that field indicator in a dichotomous key). Great to see you covering the Botrychium and the Ophioglosum. The Botrychium mormo are just begining to emerge from the leaf litter in northern Minnesota... I found a few more new populations this week. Best regards, Jason Husveth

Cathy Meyer said...

My understanding was that rattlesnake fern was named for the unfurling fertile frond, which was supposed to resemble a rattlesnake tail.