Why I had to become a fern detective - Adiatum 'Imbricatum'?

[Chris_W]

Okay, so I bought a large number of fern starts this year from a grower in Florida but they tend to sell the plants only by common name. When I inquired further about the specific varieties/species/cultivars they had to do a lot of searching to see which specific varieties they were propagating of all their ferns. A couple ferns don't actually match what they were supposedly selling, so I'm having a hard time identifying a few of them.

The maidenhair ferns were supposed to be Eastern maidenhair, Adiatum pedatum, but then the invoice listed it as Adiatum pedatum 'Imbricatum'. I asked them to clarify and they said they are just Adiatum pedatum, but that really got me wondering so I did some more digging... In my references I can find Adiatum aleuticum 'Imbricatum' but NOT pedatum 'Imbricatum'. So I compared these to my A. pedatum and they are distinctly different.

According to my references, Adiatum pedatum, the Eastern maidenhair fern, has segments that are more rounded and the leaflets (the pinnules) are held in the same plane as the fronds while Adiatum aleuticum has twisted pinnules that are out of the plane of the fronds. Based on this, and comparing it to my oldest Adiatum pedatum, I'm pretty certain that the plants I have are Adiatum aleuticum 'Imbricatum'. They are growing shorter and denser than any pedatum I've grown, but they have the characteristics of aleuticum.

Here are some pictures for you:

This is Adiatum pedatum, the Eastern maidenhair fern

This is the plant that I bought this year, likely Adiatum aleuticum 'Imbricatum'

Here is another shot of my new ferns.

So do any of you fern experts think I have this sorted out correctly? Let me know what you think.

Thanks,

Chris

[lessa's dh]

I'll dig out our Fern book and see what I can do to help you Chris

[lessa's dh]

Depending on the height, that first picture you have up there actually looks a bit like Adiantum Aleuticum "Subpumilum" but the other two certainly also have that look. Imbricatum supposedly grows from 6 - 12 inches in height while the Subpumilum is in the 3 - 6 inch range. According to my book, the eastern maidenhair ferns (A. Pedatum) will grow from 18 - 24 inches in height.

[isadora]

I get really confused about the ferns sometimes, but I have found the fern library to be useful when I couldn't quite identify something from one of my references. http://hardyfernlibrary.com/ferns/home.cfm