Botanical candidates for the lotus (tree) are discussed in the Lotophagi article.
The lotus tree is also mentioned in the Bible at Job 40:21-22, verses which refer to a large hippopotamus-like creature referred to as "behemoth". The passage states: "He lies under the lotus trees, In a covert of reeds and marsh. The lotus trees cover him with their shade; The willows by the brook surround him." (NAB)