432 MISC. PUBLICATION" 42 3, U. S. DEPT. OF AGRICULTURE 



14. SOPHORA 



Shrubs or perennial herbs; leaves pinnate, with several or many 

 leaflets; flowers in racemes, the petals white, blue, or lilac; stamens 10, 

 separate to the base or very nearly so; pods flat or turgid, moderately 

 torulose to moniliform, tardily dehiscent. 



The herbage and seeds of some (perhaps all) of the species are 

 poisonous to livestock when eaten in quantity. The herbaceous 

 species, which resemble some species of Astragalus, colonize freely by 

 means of horizontal roots and thus are efficient soil binders, especially 

 in the sandy areas of northeastern Arizona. Several shrubby and 

 arboreous species from different parts of the world are grown as 

 ornamentals and the native S. arizonica and S. jormosa, with their 

 large wisteria-colored flowers, are well worth cultivating. 



Key to the species 



1. Plants shrubby, up to 3.5 m. high; leaves coriaceous, evergreen; seeds red; 



leaves and twigs sericeous, at least when young; corolla lilac or violet; pods 



flat, about 10 mm. wide, moderately torulose (2). 



2. Leaflets acutish to obtuse, not more (usually less) than 10 mm. wide; upper 



calyx teeth 1 to 1.5 mm. long; corolla about 22 mm. long, lilac, the 



banner petal obovate-oblong (distinctly wider above the middle), about 



two-thirds as wide as long, the keel petals with claws less than half as 



long as the blades 1. S. arizonica. 



2. Leaflets obtuse or slightly retuse to acutish, up to 12 mm. wide; upper calyx 



teeth 2.5 to 3 mm. long; corolla about 16 mm. long, violet, the banner 

 petal broadly oval (not wider above the middle), four-fifths as wide as 

 long, the keel petals with claws one-half to three-fifths as long as the 



blades 2. S. Formosa. 



1. Plants herbaceous, seldom more than 30 cm. high; leaves not coriaceous or 

 evergreen; seeds not red; pods turgid, about 5 mm. wide, usually monil- 

 iform (3). 



3. Leaflets narrowly linear, 15 to 25 mm. long, pubescent on both faces; corolla 



blue ; plant velvety-tomentose 3. S. stenophylla. 



3. Leaflets oblong or oblong-obovate, commonly not more than 10 mm. long, 

 glabrous or glabrate above; corolla white or ochroleucous; plant seri- 

 ceous 4. S. SERICEA. 



1. Sophora arizonica S. Wats., Amer. Acad. Arts and Sci. Proc. 11: 



135. 1876. 

 Mohave County, "Cactus Pass and on White Cliff Creek" (Bigelow, 

 the type collection), foothills of Hualpai Mountain, Big Sandy River, 

 60 miles southeast of Kingman, about 4,000 feet, dry rocky hillsides 

 and banks of arroyos, with Quercus turbinella, Canotia, etc., March. 

 Known only from western Arizona. 



2. Sophora formosa Kearney and Peebles, Wash. Acad. Sci. Jour. 29: 



482. 1939. 



Graham County, foothills of the Pinaleno Mountains (Maguire 

 10993, the type collection, Humphrey in 1937, Kearney and Peebles 

 14233), about 3,500 feet, habitat similar to that of S. arizonica, asso- 

 ciated with Quercus turbinella, Yucca, Dasylirion, Prosopis, Larrea, 

 and Fouguieria, April. Known only from southeastern Arizona. 



Both this species and the closely related S. arizonica are very local, 

 but are fairly abundant at the stations where they occur. They 

 appear to be relict species, barely holding their own under present 

 conditions. 



