564 



TREES OF NORTH AMERICA 



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or olive-green bark, forming a narrow upright irregular head, and glabrous slightly 

 zigzag light yellow or pale olive-green and glaucous branchlets armed with thin 

 straight or curved spines Y long. Bark thin, smooth, pale olive-green, becoming 

 near the base of old trunks reddish brown, ^' 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 Cali- 

 fornia, and southward into Sonora and Lower California. 



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 numer- 

 ous small or few and ample membranaceous or coriaceous leaflets; stipules minute, 

 deciduous; stipels often 0. Flowers in terminal or axillary racemes, with linear mi- 

 nute deciduous bracts and bractlets; calyx broadly eampanulate, often slightly tur- 

 binate or obconic at the base, obliquely truncate, the short teeth nearly equal or the 2 

 upper subconnate and often somewhat larger than the others ; disk cupuliform, gland- 

 ular, adnate to the calyx-tube; corolla papilionaceous; petals white or violet blue, 

 unguiculate; standard obovate or orbicular, usually shorter than the keel-petals; 

 wings oblong-oblique; keel-petals oblong, suberect, as long as the wings or rather 

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

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

 the middle; ovary short-stipitate, contracted into an incurved style, with a minute 

 truncate or slightly rounded capitate stigma; ovules numerous, suspended from the 

 inner angle of the ovary, superposed, amphitropous. Legume terete, much contracted 

 between the seeds, woody or fleshy, usually many-seeded, each seed inclosed in a 

 separate cell, indehiscent. Seed, oblong or oval, sometimes somewhat compressed ; 

 seed-coat thick, membranaceous or crustaceous ; cotyledons thick and fleshy; radicle 

 short and straight or more or less elongated and incurved. 



Sophora is scattered over the warmer parts of the two hemispheres, with about 

 twenty species; of the six North American species two are small trees. Several of 

 the species produce valuable wood, and from the pods and flower-buds of the Chinese 

 Sophora Japonica, L., a dye is obtained used to dye white cloth yellow and blue cloth 



