LEGUMINOS^: 61.) 



2. Cercidium Torreyanum Sarg. Green-barked Acacia. Palo Verde. 



Leaves few and scattered, 1' long, hoary-tomentose when they first appear, puberulous 

 at maturity, with a slender petiole and 2 pinnae, with 2 or 3 pairs of oblong obtuse glaucous 

 leaflets narrowed toward the somewhat oblique base, iV-i' long; unfolding in March and 

 April and falling almost immediately when fully grown. Flowers ' in diameter, on slender 

 pedicels f'-l' long, in 4 or 5-flowered racemes about 1' in length, with small acute mem- 

 branaceous caducous bracts. Fruit ripening and falling in July, 3'-4' long, l'~i' wide, 

 2-8-seeded, slightly turgid, often somewhat contracted between the seeds, frequently 

 grooved on the ventral suture; seeds turgid, ' long. 



A low intricately branched tree, leafless for most of the year, 25-30 high, with a short 

 often inclining trunk 18'-20' in diameter, stout spreading branches covered with yellow 



Fig. 563 



or olive-green bark, forming a wide open irregular head, and glabrous slightly zigzag light 

 yellow or pale olive-green and glaucous branchlets armed with thin straight or curved 

 spines \' long. Bark thin, smooth, pale olive-green, becoming near the base of old trunks 

 reddish brown, f thick, furrowed and separating into thick plate-like scales. Wood 

 heavy, not strong, soft, close-grained, light brown, with clear light yellow sapwood. 



Distribution. Sides of low canons and depressions, and sandhills of the desert; valley 

 of the lower Gila River, Arizona, to the Colorado Desert of southern California, and south- 

 ward into Sonora and Lower California; when in flower in early spring the conspicuous 

 and most beautiful feature of the vegetation of the Colorado Desert. 



11. SOPHORA L. 



Trees or shrubs, with minute scaly buds, unarmed terete branches prolonged by an 

 upper axillary bud, and fibrous roots. Leaves unequally pinnate, with numerous small 

 or few and ample thin or coriaceous leaflets; stipules minute, deciduous; stipels often 0. 

 Flowers in terminal or axillary racemes, with linear minute deciduous bracts and bract- 

 lets; calyx broad-campanulate, often slightly turbinate or obconic at base, obliquely 

 truncate, the short teeth nearly equal or the 2 upper subconnate and often somewhat 

 larger than the others; disk cupuliform, glandular, adnate to the calyx-tube; corolla papil- 

 ionaceous; petals white or violet blue, unguiculate; standard obovate or orbicular, usually 

 shorter than the oblong, suberect keel-petals, as long or rather longer than the oblong- 

 oblique wings, overlapping each other at the back, barely united; stamens free, or 9 of 

 them slightly united at base, uniform; anthers attached on the back near the middle; ovary 

 short-stipitate, contracted into an incurved style, with a minute truncate or slightly 



