VOI,. II.] 



BUCKTHORN FAMILY. 



405 



2. RHAMNUS L. Sp. PI. 193. 1753. 



Shrubs or small trees, with alternate pinnately veined and (in our species) deciduous 

 leaves, and small axillary cymose racemose or paniculate, perfect or polygamous flowers. 

 Calyx-tube urceolate, its limb 4-5-toothed. Petals 4-5, short-clawed, mainly emarginate and 

 hooded, or none. Disk free from the 3-4-celled ovary. Style 3-4-cleft. Drupe berry-like, 

 oblong or globose, containing 2-4 separate nutlet-like stones. Seeds mainly obovoid; endo- 

 sperm fleshy; cotyledons flat or revolute. [The ancient Greek name.] 



About 75 species, natives of temperate and warm regions. Besides the following, some 6 

 others occur in the western United States and British America. 

 Flowers dioecious or polygamous; nutlets grooved. 



Petals present; flowers mainly 4-merous. 



Leaves broadly ovate; branches thorny; drupe with 3-4 nutlets. 

 Leaves ovate-lanceolate; drupe with 2 nutlets. 



Petals none; flowers 5-merous; drupe with 3 nutlets. 

 Flowers perfect; nutlets smooth. 



Umbels peduncled; leaves acute; calyx catnpanulate. 



Umbels sessile; leaves obtuse; calyx hemispheric. 



1. R. cathartica. 



2. R. lanceolata. 



3. R. alnifolia. 



R. Caroliniana. 

 R. Frangula. 



i. Rhamnus cathartica L/. Buck- 

 thorn. (Fig. 2391.) 



Rhamnus cathartica L- Sp. PI, 193. 1753. 



A shrub, 6-2o high, the twigs often end- 

 ing in stout thorns. Leaves glabrous, peti- 

 oled, broadly ovate or elliptic, i^ / -2j^ / long, 

 about \ f wide, regularly crenate or crenulate, 

 acute, obtuse or acuminate at the apex, ob- 

 tuse or acutish at the base, with 3-4 pairs of 

 veins, the upper running nearly to the apex; 

 flowers dioecious, greenish, about i" wide, 

 clustered in the axils, unfolding a little later 

 than the leaves; petals, stamens and calyx- 

 teeth 4; petals very narrow; drupe globose, 

 black, about 4" in diameter; nutlets 3-4, 

 grooved. 



In dry soil, escaped from hedges, New Eng- 

 land, the Middle States and Ontario. Intro- 

 duced from Europe and native also of northern 

 Asia. May-June. Called also Hart's-thorn, 

 Rhineberry, and Waythorn. The berries yield a 

 dye, and have powerful medicinal properties. 



Rhamnus lanceolata Pursh. L/ance-leaved Buckthorn. (Fig. 2392.) 



Rhamnus lanceolata Pursh, Fl. Am. Sept. 

 166. 1814. 



A tall erect shrub, with smooth gray- 

 ish bark, and unarmed mostly puberulent 

 branches. Leaves short-petioled, i f ~2> l /2 f 

 long, }^ f -\ f wide, ovate-lanceolate, ob- 

 tusish or acuminate at the apex, acute or 

 obtuse at the base, glabrous or nearly so 

 above, more or less pubescent, especially 

 on the veins beneath, finely serrulate; 

 veins 6-7 pairs; flowers axillary, 2-3 to- 

 gether, greenish, about \ l /t" broad, 

 mostly dioecious, appearing with the 

 leaves; pedicels i // -2 // long; petals, 

 stamens and calyx-teeth 4; drupe black, 

 about 3" in diameter, obovoid -globose; 

 stigmas 2; drupe containing 2 grooved 

 nutlets. 



In moist soil, Pennsylvania to Iowa and 

 Nebraska, south to Alabama and Texas. 

 May. 



