We jumped out of the car and I cut one open to see what they were like. The inside was white and smelled strongly of watermelon. I took a small bite and Tanya immediately turned to me and told me that these were poisonous, information that would have been more useful moments earlier.
The melon tasted bitter and I spit out the piece I had bitten off. This was probably why the camels we saw grazing earlier in the day had left this patch alone.