OTHER POD-BEARERS 189 



takes him on a wood-gathering expedition. Stopping 

 where a shrubby mesquite sprawls, he liitches his team to a 

 chain or rope that Lays hold of the trunk, and hauls the 

 plant out by its roots. And what roots the mesquite has 

 developed in its search for water! There is a central tap 

 root that goes down, down, sometimes sixty feet or more. 

 Secondary roots branch out in all directions, interlock, 

 thicken, and form a labyrinth of woody substance, in 

 quantity and quality that makes the timber above ground 

 a negligible quantity. This wood is cut into building and 

 fencing materials — two great needs in the desert. The 

 waste makes good fuel, and every scrap is precious. 

 Posts, railroad ties, frames for the adobe houses, furniture, 

 fellies of wheels, paving blocks, and charcoal are made of 

 this wonderful tree's root system. A gum resembling gum- 

 arabic exudes from the stems. 



The Screw-bean 



P. puhescenSy Benth. 



The screw-bean or screw-pod mesquite is a small slender- 

 trunked tree with sharp spines at the bases of the hoary 

 foliage. The marked distinction between this species and 

 the preceding one is in the fruit, which makes from twelve 

 to twenty turns as it matures, and forms when ripe a 

 narrow straight spiral, one to two inches long; but when 

 drawn out like a coiled spring the pod is shown to be more 

 than a foot in length. These sweet nutritious pods are a 

 most useful fodder for range cattle, and the wood is used 

 for fencing and fuel. This tree grows from southern Utah 

 and Nevada through New Mexico and Arizona into San 



