Serenity dose have a tree, it’s small, the needles made of wire, and is mostly just scrap metal welded into the from of something resembleling a tree. But they like it. They have one string of lights that are just a bit to long, the “beads” are shells on string, and the tinsel is a strip of use-to-be-white fabric that is just a little to short. In way of ornaments there only about 11, one for each member of the crew. Malcolm’s is is a tiny Serenity, Zoë’s is a bootlace bow, Wash’s is a leaf, Kaylee’s is a strawberry, Jayne’s is a tiny Vera(he spent a descent amount to get it custom made), Simons is a small “classic” looking med kit, River’s is a small pair of glass ballet shoes, Book’s is a cross, Inara’s is buddhist statue(which I cannot identify at risk of religious insensitivity). This tree is in no way meant to be religious, it was solely there to help with crew moral, Malcolm was insistent on this when Jayne and Kaylee came on back from a rest shop saying they bought it. The only reason Malcolm was even convicted to keep it in the first place was because Wash piped up and said he didn’t know what a Christmas tree was and never seen anything resembling one, never even herd of the concept. This broke the crews hearts, and Malcolm then promptly ordered Jayne and Kaylee to go back into town and get the normal fixings for a tree and anything the couldn’t find, to make it. They only found lights. Over time they found and made everything they needed and set it up, explaining things to Wash as they went. Once the tree was done the crew just stared at it, as none of them had seen a decorated tree in a very long time or ever. Wash enjoys it the most he loves how colorful it is.