Pistilidium or Pistillidium: How To spell?
The word Pistilidium is misspelled against Pistillidium, a noun meaning "Same as Archegonium."
Pistillidium has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings pisti & idium which should not be misspelled with single 'L'
Wrong Spelling:  pisti-l-idium  Correct Spelling:  pisti-ll-idium 
Check more misspelled words of Pistillidium to spell it correct.