"It is believed the early Mormons gave this giant Yucca its name, seeing in it's grotesquely extended arms a symbol pointing tot he promised land they were seeking."
This time of the year is the best time to visit this part of the desert and given the date stamp on the postcard of Dec 29, 1947, it gives me an idea of maybe a day trip during the holiday break. Below are some image of Joshua trees I've taken over the years, typically somewhere in the high desert in California. I would never hesitate to stop the car and stand next to these towering Yuccas.
Of course, the most famous Joshua tree of all is the one from "The Joshua Tree" album by that Irish band as shown below on the inside cover. Yeah, back when music was actually packaged in somewhat decent artform. The U2 images were taken by photographer Anton Corbijn.