724 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



DOUBTFUL SPECIES. 



Ceanothus mocinianus DC. Prodr. 2: 32. 1825. 



Ceanothxjs pauciflobus DC. Prodr. 2: 33. 1825. Both this and the preceding 

 were based upon plates of Sesse and Mocino. It is doubtful whether they 

 belong to the genus. 



10. SAGEBETIA Brongn. Ann. Sci. Nat. 10: S59. 1827. 



Shrubs or small trees, the branchlets slender, often spinose; leaves subop- 

 posite, short-petiolate, pinnately nerved, entire or serrate; flowers minute, 

 glomerate along the branches of the panicle ; calyx 5-lobate ; petals 5, cucuUate, 

 clawed ; stamens 5 ; fruit drupaceous, juicy, the 3 nutlets coriaceous, inde- 

 hiscent. 



Many of the species have edible fruit. The leaves of S. theezans (L.) 

 Brongn. are used in China as a substitute for tea. 



Leaves obtuse or roundetl at apex, obtuse at base, 1 to 2 cm. long__l. S. wrightii. 

 liCaves acute or acuminate, rounded or subcordate at base, 3 to 6 cm. long. 



2. S. elegans. 



1. Sageretia wrightii S. Wats. Proc. Amer. Acad. 20: 358, 1885. 



Sonora to Jalisco ; type from Santa Cruz, Sonora. Western Texas and 

 southern Arizona. 



Densely branched shrub, 0.5 to 3 meters high, the branchlets spinose ; leaves 

 oblong to elliptic, obscurely serrulate or entire, lustrous, tomentulose when 

 young but soon glabrate ; inflorescence little exceeding the leaves. 



This was reported by Hemsley as S. micJiauxii Brongn. 



2. Sageretia elegans (H. B. K.) Brongn. Ann. Sci. Nat. 10: 359. 1827. 

 Rhammis elegans H. B. K. Nov. Gen. & Sp. 7: 53. pZ. 619. 1825. 



Sinaloa to Veracruz and Chiapas. Central America, Colombia, and Peru. 



Slender sarmentose shrub, 3 to 4.5 meters high ; leaves lanceolate to ovate- 

 elliptic, deciduous, serrulate, tomentulose beneath when young but soon 

 glabrate ; panicles very large and broad, tomentose, the flowers whitish ; fruit 

 6 to 8 mm. in diameter. 



Sageretia salamensis Loesener,* described from Guatemala, is probably not 

 separable from this species. 



11. RHAMNUS L. Sp. PI. 193. 1753. 



Unarmed trees or shrubs ; leaves opposite, petiolate, persistent or deciduous, 

 pinnate-nerved; entire or toothed ; flowers green, perfect or polygamo-dioecious, 

 axillary, solitary, fasciculate, or umbellate ; calyx 4 or 5-lobate ; petals 4 or 5 

 or none ; stamens 4 or 5 ; fruit drupaceous, 2 to 4-celled, the nutlets osseous or 

 cartilaginous. 



The species are known by the English name " buckthorn." R. cathortica L., 

 of Europe, yields a green dye, and the fruit and bark have purgative properties. 

 The dried bark of R. purshiana DC, of the western United States, is an official 

 drug, known as " cascara sagrada." The bark is yellow within, with a bitter 

 and rather nauseous taste ; its extract is used in medicine as a laxative. R. 

 californica Eschsch. also has similar properties, and much of the drug of com- 

 merce is probably derived from this species. ^ 



* Verb. Bot. Ver. Brand. 51 : 30. 1910. 



