I was on a discussion thread at iNaturalist for an observation of Aralia species in Catonsville, Md. The non-native Japanese Angelica Tree (A. elata) has been escaping from cultivation and is reported in several Maryland counties.
How to distinguish A. elata from the native Devil’s Walkingstick (A. spinosa) in winter? David Sibley’s guide says that A. elata is “less spiny,” but that doesn’t help very much.
Fortunately, Maraea Harris of Meadowlark Botanical Gardens pointed out for me (we were on an invasives removal work day) a cultivated example of A. elata, specifically the variety “Silver Umbrella” with variegated leaves (in the growing season, of course).
You can see that the younger stems (at left) are lightly armored, but the older trunks show only vestiges of their spines. This observation squares with a horticultural blog post from Milan Havlis.
Also of note: cultivars are grafted, and can revert to the wild type. I wonder how many of our escapes are from cultivars.