You know...there is this thing called a search engine where you can probably find lots of information...this was the first result I found, and as it's St Louis Botanical Garden, should be a good reference.

Here is a link that might be useful: Link

It sounds like the tag is probably for Aruncus dioicus âÂÂKneiffiiâÂÂ- that's the 30-36" one. The regular A. dioicus gets to the 4'-6' range. The A. aethusifolius is indeed a short one-footer. BUT I think the 'Kneiffi' is often sold with the dwarf name - it took me a long time (until just recently) before I finally clued-in that my 3' goatsbeard was NOT the dwarf type! :-)

dbarron, I'm actually confused because the info I've obtained from these new-fangled internet search engine thingies and the in-real-life tag that came from the plant specimen conflict! Hence the question here.

Here is the tag from the planting in question.

woodyoak, I think either the height or the species indicated on the tag is incorrect. I moved my goatsbeard closer to the front of my garden today, and I guess I'll just have to wait and see what it turns out to be.

In my experience, A. aethusifolius has extremely finely cut foliage. Perhaps that will help you make a correct ID.

If laceyvail's personal observation doesn't help, then yep, the proof is in the pudding, and time will have to tell.

It certainly wouldn't be the first time that probably any of us ever got something that was mislabeled...boy they're bad at that.

laceyvail and dbarron, Yes I think it is A. aethusifolius from the foliage, which looks just like christinmk's photos from this thread. I love the ruby red from the 2nd picture...hope I have that to look forward to this fall.

I still need something tall (4 to 6 feet) to go in back against the fence that will do well in shade. Would it look silly to put an A. dioicus right behind my A. aethusifolius?

Well, what comes to mind for me...is that everyone will wonder why this one is so much smaller than that one?

At best, you basically have a large blob, with a smaller blob in front, of the same thing. It's not usually done, but then again, people always suggest planting in multiples of three, so why not ? :)
I'm a dabbler, I don't have room for three of anything...it's almost always singles, so I can get the next exciting plant in also.

Perhaps the foliage is different enough between the two that they won't read as "big blob and little blob," although the blooms look like they might be almost identical. If I go this route, I might try and break in between them with layer of solomon's seal. I suppose I could always try and move the dwaft goatsbeard if I don't like them together, though I understand they don't like to be transplanted.

Thanks to all for the help on this issue.

Yep, you really don't know till you try. And what another person likes or doesn't, will likely mean nothing to your individual taste.

I just went out and took pictures of my different ones.... The picture below shows the leaves from the three different-sized ones I have. The mid-sized one is the one that had the same sort of tag as the OP's. I think maybe the species is right as it seems to be self-fertile - seeds A LOT!, so it's either self pollinated or being pollinated by the A. dioicus 30-40' away... The dwarf one is REALLY dwart so you can't mistake that one :-)

{{gwi:262140}}

The A. dioicus in my garden looks quite different from the mid-sized or small ones, so I don't see any problem putting them together. But do think about the seeding issue if you've got the mid-sized one - that will become a very dense and growing clump as it gets bigger both maturing and seeding.

{{gwi:262141}}

They're definitely different, but all except the dwarf look enough like a blackberry leaf....

woodyoak, Hmm, now I'm thinking it might be the mid-sized cultivar. With maturity, I can see how it might possibly come to look exactly like yours. Doesn't seem quite as dwarf as the one in your photo unless my perspective on the scale is way off. Thank you for sacrificing your leaves!

It's rather hard to tell from your picture, but it does look a bit bigger than the dwarf. Plant it and see how it does...?

I'm a dabbler, I don't have room for three of anything...it's almost always singles, so I can get the next exciting plant in also

You and I are "birds of a feather". That is very much me.