What is a Jacob's staff? Here are some definitions.
Noun
(surveying) A single straight rod or staff, pointed and iron-shod at the bottom, for penetrating the ground, and having a socket joint at the top, used, instead of a tripod, for supporting a compass.
Verbascum thapsus, the common mullein.
The ocotillo, one of Fouquieria, a genus of desert shrubs of southwestern United States and Mexico having slender naked spiny branches that after the rainy season put forth foliage and clusters of red flowers.