The Joshua tree stands alone in the desert, twisted and upright, so dream books read it as perseverance and guidance in a barren stretch of life. Its raised arms are also taken as an image of reaching out.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.