Here in the mid-Atlantic region I sometimes find it difficult to distinguish between Ashy and Lancet Clubtails, especially the females. The Ashy Clubtails here don't darken significantly with age, unlike in other regions. Thus they are the same color as Lancet Clubtails, and the pattern on the abdomen is similar. The Lancet Clubtail is noticeably smaller, but that doesn't always help if you don't see them next to each other. Individuals vary within a size range. If a given dragonfly is too ambiguous, I just throw up my hands and call it a "Lashy" Clubtail!

The male Ashy Clubtail's abdomen has a small triangular yellow spot on segment 8. There may be a large yellow area on segment 9, but this is sometimes lacking. The club is extremely narrow, with thin yellow lines where the club flares out from the abdomen. The Lancet Clubtail by contrast has a yellow "lancet" shape extending all the way down segment 8. The large yellow area on segment 9 is always present. The club is wider than on the Ashy Clubtail and has more pronounced yellow coloring on the flared edges.

The female Ashy Clubtail's abdomen may have no yellow at all on segments 8 and 9. If yellow is present, it will be a tiny triangle on segment 8 and a thin line on segment 9. The Lancet Clubtail by contrast has a yellow "lancet" shape extending all the way down segment 8, and [usually] a large yellow area on the top of segment 9.