top to_bottom, _dryopteris_intermedia, _dryopteris_intermedia_X_marginalis, _dryopteris_marginalis, _jackson_county, _alabama_1, I_AMC7042
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© Copyright Alan Cressler 2011

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I discovered this plant 28 years ago on June 21, 1981. I suspect the plant is very old considering the multi-crowned rhizome is almost two feet long. The sterile hybrid between Dryopteris intermedia and Dryopteris marginalis is extremely rare considering how often the parent plants grow in close proximity.

Although Dryopteris marginalis is common in northern Alabama it is rarely seen growing on limestone. I can only think of a few cave entrances where I have observed it. The species is most often observed in sandstone boulder fields and north aspect cliff faces around the plateau top.

Dryopteris intermedia is not overly common in northern Alabama but is encountered in moist sandstone canyons of the Cumberland Plateau. Again it is almost never seen growing in cave entrances. The cave associated with this site blows 56 degree F. air strongly when the surface temperature is warm. This creates an interesting micro-habitat that remains cold all summer.

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title top to bottom, dryopteris intermedia, dryopteris intermedia X marginalis, dryopteris marginalis, jackson county, alabama 1
date yyyymmdd hr:mn 2009:06:20 13:27:08
source Flickr
flickr_agent alan_cressler

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