Greek kalymma (stem kalymmat-) ‘head-covering, hood, veil’ + Greek anthos ‘flower’ + Latin –ium, a name-building suffix (the compound should correctly be Callymmatanthium). Translated by Ritter as Kappenblüher ‘hood flowerer’. For the stem-like “protective hood” (Schutzkappe) in which the flower buds develop.
Callymmanthium substerile. Image credit: Michael Wolf / CC BY-SA 3.0 (edited)
Maarten H.J. van der Meer (2023 Jul 14). Calymmanthium. Dictionary of Cactus Names. Retrieved from https://www.cactusnames.org/calymmanthium