Quilwort or Quillwort: How To spell?
The word Quilwort is misspelled against Quillwort, a noun meaning "Any plant or species of the genus Isoetes, cryptogamous plants with a cluster of elongated four-tubed rushlike leaves, rising from a corm, and containing spores in their enlarged and excavated bases. There are about seventeen American species, usually growing in the mud under still, shallow water. So called from the shape of the shape of the leaves."
Quillwort has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings qui & wort which should not be misspelled with single 'L'
Wrong Spelling:  qui-l-wort  Correct Spelling:  qui-ll-wort 
Check more misspelled words of Quillwort to spell it correct.