Greek chamai ‘on the ground’ + Cereus, the name of a genus of columnar cacti and a designation for columnar cacti in general. For “the creeping or depressed habit of the plant” (Britton & Rose).
Chamaecereus silvestrii. Image credit: Krzysztof Ziarnek / CC BY-SA 4.0
“Botanical Latin is essentially a written language, but the scientific names of plants often occur in speech. How they are pronounced really matters little provided they sound pleasant and are understood by all concerned.”
Maarten H.J. van der Meer (2023 Jul 14). Chamaecereus. Dictionary of Cactus Names. Retrieved from https://www.cactusnames.org/chamaecereus