154. DALEA SPINOSA DALEA, INDIGO BUSH. 27 



partly inclosed in the accrescent calyx, membranous, sometimes ribbed, gener- 

 ally indehiscent and containing a single oblong or reniform seed with coriaceous 

 testa and without albumen. 



Genus confined to the New World and represented by glandular-punctate herbs 

 and shrubs, and in the arid regions of southwestern United States one or two 

 species of small trees. 



(Genus named in compliment to Dr. Samuel Dale, an English botanist.) 



154. DALEA SPINOSA, GRAY. 



DALEA, INDIGO BTJSH. 

 Ger., Dorniger Dalea' Fr., Dalea d epines; Sp., Dalea espinosa. 



SPECIFIC CHARACTERS: Leaves simple, mostly^ to in. long, few and scat- 

 tering, cuneate to linear-oblong, sessile or nearly so, entire or undulate-margined 

 or on vigorous shoots coarsely serrate, hoary-pubescent, marked with few large 

 glands and very early deciduous, remaining on the branches only a few weeks; 

 branchlets reduce to slender sharp spines clothed with very minute hoary pubes- 

 cence and bearing prominent scattered glands. Flowers (appearing in early sum- 

 mer) scarcely \ in. long, sessile or nearly so, in loose racemes, 1 to H in. long, with 

 hoary-pubescent spinescent rachises furnished with minute bracts; calyx-tube 

 10-ribbed and bearing about five conspicuous glands between the dorsal ribs, 

 lobes ovate or rounded and much shorter than the tube; petals dark violet-blue, 

 the standard reflexed and bearing two conspicuous glands, wings and keel about 

 equal in size, each furnished with a lobe near the base and attached to the stam- 

 inal tube only by their bases. Fruit a pubescent 1 -seeded ovate compressed pod 

 about twice as long as the accrescent calyx and tipped with the remnants of the 

 style; seed reniform, about |- in. long, pale brown with irregular darker spots. 



(The specific name is the Latin for spinose, referring to the spinose nature of 

 the branchlets.) 



A low tree occasionally 18 or 20 ft. (6 m.) in height, with long 

 irregular branches and short trunk, sometimes 18 in. (0.45 m.) in 

 diameter, clothed with a thin grayish-brown bark, which becomes 

 fissured finally into shallow, firmly adherent ridges. More often it is 

 rather an intricately branched shrub than a tree. 



No one but those who have seen the arid desert regions of the south- 

 west can fully understand the singular aspect of this tree, bluish-gray 

 in color throughout, with low, sprawling branches, which finally 

 terminate in a profusion of spines and bearing leaves for only a few 

 weeks in the year. 



HABITAT. Southern California about the eastern washes of the 

 San Jacinto Mountains the valley of the Gila River in Arizona and 

 in Lower California. 



PHYSICAL PROPERTIES. The wood of this species is rather hand- 

 some, of coarse grain, with small quite evenly distributed ducts and 

 fine medullary rays. It is of a walnut-brown color with thick creamy- 

 white sap-wood. Specific Gravity, 0.5536; Percentage of Ash, 

 4.04; Relative Approximate Fuel Value, 0.5312; Weight of a Cubic 

 Foot in Pounds, 34. 50. 



