silicle (sil-ickle) and silique (sil-eek): two-chambered (loculed) fruits on species belonging to the mustard (Brassicaceae) family; when opened, a central septum (or wall) between locules is revealed, to which the seeds are attached.

As far as I know, the only plant family with silicles or siliques is the mustard family. I have always found it a little amusing that there are two names for essentially the same thing, the major difference being the shape. A silicle is a short, wide, flattened or rounded fruit; a silique, on the other hand, is long and narrow.

closeup photo of blue mustard siliques
These are the siliques of blue mustard (Chorispora tenella).

For help remembering which is which, just remember that a silique is “long and sleek”, and a silicle is everything else (heart shaped, spherical, or a flattened circle).

The photo at the top of the post is of the silicles of field pennycress (Thlaspi arvense).