This hadith has been narrated on the authority of Ibn Ka'b through another chain of transmitters but with " "the similitude of the disbeliever is that of a cypress tree".
Sahih Muslim Book 52, Hadith 51
← Previous Hadith This hadith has been narrated through a couple of other chains of transmitters, one which says "the similitude of the disbeliever" instead and another which agrees with the wording of the previous hadith.

Sahih Muslim Book 52, Hadith 50 Next Hadith → There is a tree amongst trees, the leaves of which do not wither and that is like a Muslim; tell me which that (tree) can be? The people began to think of the trees of the forest. Abdullah said: I thought that it could be the date-palm tree, but I felt hesitant (to say that). They (the Companions) then said: Allah's Messenger, (kindly) tell us which that can be? Thereupon he said: It is the date-palm tree. I made a mention of that to 'Umar, whereupon he said: Had you said that it meant the date-palin tree, this statement of yours (would have been dearer to me) than such and such things.

Sahih Muslim Book 52, Hadith 52