220 RHAMNACEAE. 
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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. 
. Buds chiefly opposite: shoots often spine-tipped. 3. 
Buds alternate: not spiny. 4. 
. Spines scarcely longer than buds. (1). R. cathartica. 
Spines long and very pungent. R. japonica. 
. Buds large (7-8 mm. long). (2). R. alpina. 
Buds small (under 5 mm. long). 5. 
. Twigs gray, often downy. (3). R. lanceolata. 
Twigs red or brown, glabrous. R. alnifolia. 
. Buds long (8-10 mm.). (Cascara sagrada). R. Purshiana. 
Buds short (scarcely 5 mm.). 7. 
. Fruiting pedicels separate. R. Frangula. 
Fruiting pedicels several in a cluster. (4). R. caroliniana. 
