POLYPETALOL'S EXOGENOUS PLANTS. 203 



alternate pinnately-veined leaves, with minute stipules, 

 and small greenisli axillary or pauicled flowers. 



B. VOLUBILIS. Stem twining; leaves oblong, acute, 

 wavy on the margin, glossy above, the veins oblique; 

 fioivers in small terminal panicles ; drupe purple. 



CEANOTHtrS, L. Jersey Tea. 



Calyx 5-cleft, colored, tube adnate to the ovary and 

 persistent, lobes connivent, deciduous ; 2)etals 5, longer 

 than the calyx, hooded, long-clawed; stamens exserted; 

 style 3-parted; druj^te dry, composed of three 2-valved, 

 1-seeded nutlets; embryo in fleshy albumen; cotyledons 

 flat. — Sliruiiy plants, with alternate, serrulate, minutely 

 stipulate, 3-ribbed leaves, and small floiuers in lateral and 

 terminal corymbs or panicles. 



C. MiCROPHYLLUS, Michx. Stem erect, diff'usely much- 

 branched; leaves perennial, small, obovate, slightly crenate, 

 3-ribbed, glossy above, with scattered hairs beneath, those 

 in the axils clustered; corymbs small, terminal. Leaves 

 2"-3" long.— Shrub, l°-2° high, yellowish. Pedicels and 

 flowers white. 



RHAMNUS. Buckthorn. 



Calyx 4-5-cleft, the tube urceolate, lined with a thin 

 disk; petals small, obovate, concave, often wanting; 

 ovary free, 2-4-celled ; styles united below ; stigmas 

 2-4 ; drupe baccate, composed of 2-4 somewhat dehiscent 

 nutlets ; seeds grooved on the back ; ra^jhe dorsal ; coty- 

 ledons leafy, revolute. — Shrubs, with alternate stipulate 

 finely-veined leaves, and small axillary clustered polyga- 

 mous or dioecious greenish flowers. 



R. OBTUSiFOLius, Gray and Torry. Somewhat thorny, 

 glabrous. Branches whitish ; leaves ovate or oblong-ovate. 



