As in malaria, among other productions, but also used in geology of sediments produced in a marshy environment and in ecology for that environment. Coined in the 1810s from Latin palūs (with a stem change to palūd-), marsh or fen. Also usable in metaphoric extensions, as in this quote from 1917 from Punch:
"Indeed one reads of some old poets who were not able to produce a mere hundred lines in a day. Under the "free-verse" system, some of the Paludal (or Marshy) School have been known to produce as many as three thousand lines in a day"