古柯树

古 = 十 + 口 : Mnemonic symbol: at least on German maps, this character actually resembles a cloister.

Oh no! Gitta Giraffe (gu) found that the golden cross (十) broke off of the cloister (古) in the space station's living room (Ø3)! She skewers a mandarin (口) on top of the cloister so that she can skewer the broken off cross back on to fix it.

柯 = 可 + 木 : Karl Marx (k) is recycling a Christmas tree (木) in front of the elevator (e1). He uses the stem (柯) to make boards for his bed of nails (可), the needles of the tree as the nails for his bed of nails and the branches of the tree to make handles for his axes (柯).

树 = 对 + 木 : Sheldon Shrimp cultivates a Christmas tree in the space station's bathroom. He is very happy that he found the right tree, just the one he imagined, and—in his mind—marks of the tree he imagined with a big green check mark.