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RHAMNAOEAE. 



RHAMNUS. Buckthorn. 

 (Family Rhamnaceae). 



Shrubs or rather small trees: 

 deciduous. Twigs rather slender, 

 rounded: pith moderate, rounded, 

 continuous, white. Buds moderate, 

 solitary, sessile or exceptionally 

 developing the first season, naked 

 (Frangula) or with some half- 

 dozen scales (Rhamnus proper). 

 Leaf-scars alternate, or in some 

 species opposite or in decussating 

 broken pairs, crescent-shaped or 

 half-elliptical, small, more or less 

 raised: bundle-traces 3 or joined 

 into a transverse series: stipule- 

 scars mostly minute, or stipules 

 small and persistent. References 

 under Adolphia. 



Cascara sagrada is much used in 

 medicine. 

 1. Buds scaly (Rhamnus). 2. 



Buds naked (Frangula). 6. 



2. Buds chiefly opposite: shoots often spine-tipped. 3. 

 Buds alternate: not spiny. 4. 



3. Spines scarcely longer than buds. (1). R. cathartica. 

 Spines long and very pungent. R. japonica. 



4. Buds large (7-8 mm. long). (2). R. alpina. 

 Buds small (under 5 mm. long). 5. 



5. Twigs gray, often downy. (3). R. lanceolata. 

 Twigs red or brown, glabrous. R. alnifolia. 



6. Buds long (8-10 mm.). (Cascara sagrada). R. Purshiana. 

 Buds short (scarcely 5 mm.). 7. 



7. Fruiting pedicels separate. R. Frangula. 

 Fruiting pedicels several in a cluster. (4). R. caroliniana. 



