The word(s) "tree" appears 42 time(s) in 40 verse(s) in Quran in Muhammad Pickthal translation.

(21) And if all the trees in the earth were pens, and the sea, with seven more seas to help it, (were ink), the words of Allah could not be exhausted. Lo! Allah is Mighty, Wise.

(22) But they were froward, so We sent on them the flood of 'Iram, and in exchange for their two gardens gave them two gardens bearing bitter fruit, the tamarisk and here and there a lote-tree.

(23) Who hath appointed for you fire from the green tree, and behold! ye kindle from it.

(24) Is this better as a welcome, or the tree of Zaqqum?

(25) Lo! it is a tree that springeth in the heart of hell.

(26) And We caused a tree of gourd to grow above him;

(27) Lo! the tree of Zaqqum,

(28) Allah was well pleased with the believers when they swore allegiance unto thee beneath the tree, and He knew what was in their hearts, and He sent down peace of reassurance on them, and hath rewarded them with a near victory;

(29) By the lote-tree of the utmost boundary,

(30) When that which shroudeth did enshroud the lote-tree,