Knotgras or Knotgrass: How To spell?

The word Knotgras is misspelled against Knotgrass, a noun meaning "a common weed with jointed stems (Polygonum aviculare); knotweed."

Knotgrass has double 'ss' in the end mispronounced as 's'
Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling: knotgra-s
Correct Spelling: knotgra-ss
Find more incorrect spellings of Knotgrass to spell right way.