of its very nature这里是后置定语,“从它的本质上说”散文比诗歌长.类似的句子可以有,China ,with a long history and culture is becoming more and more important in the world.介词短语后置对吧，with 有伴随的意思，那of是什么啊，所属还是什么。我说的类似是同为of 的类似后置定语。