Comments:VEWT 338, Егоров 78, Федотов 1, 194, Дмитриева 189, Лексика 126. The word is attested late (like many tree names), but borrowing from Russ. ильм is hardly possible; the Russian word, usually considered a Germanism (MHG ilme etc.), may equally well be explained as a Turkism (see Егоров ibid.). The resemblance of PT *ilme and PIE *l̥mo- / *olmo- is interesting, but probably accidental (if the Turkic word indeed goes back to PA *p`i̯ule).