STANDLEY — TREES AND SHRUBS OF MEXICO. 539 



Leaves simple, sometimes reduced to scales. 



Leaves reduced to scales; petals 7 or 8 1. HOLACANTHA. 



Leaves well developed ; petals 4 2. CASTELA. 



Leaves pinnate. 



Fruit samara-like 3. ALVARADOA. 



Fruit drupaceous or baccate. 



Leaflets 3 4. PICRELLA. 



Leaflets 5 or more in all or most of the leaves. 

 Carpels of the fruit 1-ovulate. 



Stigmas distinct ; leaflets usually 11 to 21 5. SIMAROUBA. 



Stigmas united; leaflets usually 5 6. QUASSIA. 



Carpels 2-ovulate. 



Carpels distinct 7. RECCHIA. 



Carpels united 8. PICRAMNIA. 



1. HOLACANTHA A. Gray, Mem. Amer. Acad. II. 5: 310. 1854. 



1. Holacantha emoryi A. Gray, Mem. Amer. Acad. II. 5: 310. 1854. 



Reported from northern Sonora. Southern Arizona ; type collected between 

 Tucson and the Gila River. 



Shrub, 2 to 3 meters high, much branched, the branches spinose, green 

 or brownish ; leaves reduced to small scales ; flowers dioecious, small, solitary 

 or clustered; fruit of 6 to 10 small drupes. "Corona de Cristo " (Arizona). 



2. CASTELA Turp. Ann. Mus. Hist. Nat. 7: 78. 1806. 



Shrubs or small trees, the branchlets spinose or spurlike ; leaves small, 

 narrow, simple, entire or nearly so ; flowers small, dioecious, solitary or 

 clustered ; sepals 4, distinct or nearly so ; petals 4 ; stamens 8 ; fruit of 1 or 

 more small drupes. 



Leaves green beneath, the pubescence not white 1. C. peninsularis. 



Leaves covered beneath with a fine whitish pubescence. 



Petals narrowly obovate; leaves narrowly obovate 2. C, texana. 



Petals broadly obovate ; leaves obovate or ovate. 



Leaves obtuse at apex 3. C. tortuosa. 



Leaves retuse 4. C. retusa. 



1. Castela peninsularis Rose, Contr. U. S. Nat, Herb. 12: 278. 1909. 

 Castelaria peninsularis Small, N. Amer. Fl. 25: 231. 1911. 



Dry plains and hillsides, Ba ja California ; type from San Jos6 del Cabo. 



Densely branched, spiny shrub, 1 meter high or less ; leaves oval or broadly 

 obovate, 1 to 2 cm. long, coriaceous ; flowers red ; petals 3 mm. long ; fruit 

 about 8 mm. long. 



2. Castela texana (Torr. & Gray) Rose, Contr. U. S. Nat. Herb. 12: 278. 1909. 

 Castela nicholsoni texana Torr. & Gray, Fl. N. Amer. 1 : 680. 1840. 

 Castelaria texana Small, N. Amer. Fl. 25 : 231. 1911. 



Castela saluhris Boas, Beitr. Anat. Syst. Simarub. 44. 1912. 



Dry plains and hillsides, Coahuila, Tamaulipas, and San Louis Potosl 

 Southwestern Texas. 



Densely branched shrub, 1 to 2.5 meters high, with stiff whitish sp'nose 

 branches ; leaves 0.5 to 1.5 cm. long, obtuse ; flowers bright red or purplish, 

 about 3 mm. long; fruit red, 6 to 8 mm. long. " Bisbirinda " (Tamaulipas) ; 

 " amargoso " (Nuevo Le6n, Texas) ; "chaparro amargoso " (Texas). 



A decoction of the very bitter bark is employed in domestic medicine for 

 fevers, intestinal disturbances, and eczema. It has astringent and perhaps 

 tonic properties. 



