Silique: A dry, dehiscent fruit of the Brassicaceae (Cruciferae) typically more than twice as long as wide, with two valves separating from the persistent placentae and septum.*
The long seed pods seen protruding below the flowers of Cleome (spider flower) are siliques. Because Cleome produce siliques, they were originally classified in the Brassicaceae (Mustard) family. Recent DNA tests have shown, however, that Cleome belongs in its own family, Cleomaceae.
*Harris, J.G., Harris, M.W. (2001). Plant identification terminology: An illustrated glossary (2nd ed.). Spring Lake: Spring Lake Publishing.