Rhamnus. RHAMNACE^E. 143 



as the seed : radicle short : cotyledons large, flat. — Shrubs or trees, often 

 thorny. Lea\es mostly alternate, simple, usually with minute stipules. Flowers 

 small, sometimes by abortion dioecious or polygamous : inflorescence various. 



1. RHAMNUS. Linn. ; Brongn. in ann. sci. nat. 10. p. 3G0 ; Endl. gen. 5722. 



rr. u ^ . , BUCKTHORN. 



[ k rom the UreeK, ramnvs, a branch ; in allusion to its numerous branches.] 



Calyx urceolate, 4 - 5-cleft. Petals 4-5, emarginate or 2-lobed, often more or less con- 

 • volute, sometimes very minute or wanting. Torus thin, lining the tube of the calyx. Ovary 

 free from the calyx, not immersed in the torus, 2 - 4-celled : styles 2-4, distinct or more 



or less connected. Fruit drupaceous, roundish, containing 2-4 cartilaginous nuts. 



Shrubs or small trees. Leaves alternate or rarely opposite, on short petioles. Flowers 

 minute, usually in short axillary clusters. 



1. Rhamnus catharticus, Linn. Common Buckthorn. 



Erect : branches thorny at the summit : leaves ovale, denticulate-serrate ; flowers fascicled, 

 polygamo-dioecious, mostly tetrandrous ; fruit nearly spherical, 4-seeded. — Eng. hot. t. 1629; 

 Torr. fl.\.p. 263 ; Twr. cj- Gr. Jl. N. Am. 1. p. 260. 



A large spreading shrub, with grayish bark. Leaves spreading and somewhat opposite, 

 1-2 inches long, with a short abrupt acumination, smooth, with 5-7 strong nearly longi- 

 tudinal veins. Pedicels 3-4 lines long. Fertile flowers with lanceolate sepals, linear-oblong 

 petals and abortive stamens. Styles free at the summit, recurved : stigmas somewhat clavate. 

 Sterile flowers with ovate sepals and petals, and an abortive ovary. Fruit black, nauseous 

 and cathartic. 



In the Highlands of New-York, naturalized in many retired situations. Fl. May. — The 

 berries were formerly employed as a cathartic, but they are drastic. The syrup of buckthorn 

 is still a common article of the materia medica, but is chiefly used for uniting other medicines. 

 The pigment called sap green is prepared from the juice of the berries mi.xed with alum. 



2. Rhamnus alnifolius, I'Herit. Alder-leaved Buckthorn. 



Erect, without spines ; leaves oval, acuminate, serrate, somewhat pubescent on the veins 

 underneath ; flowers polygamo-dioecious, solitary or aggregated, pentandrous (or rarely te- 

 trandrous), apetalous ; styles 3, very short, at first united nearly to the summit ; disk some- 

 what flesliy ; fruit roundisli-turbinatc. — "Vllcrit. sert. p. 5 ;" Torr. Jl. I. p. 263 ; DC. 

 prodr. 2. p. 25 ; Hook. fl. Bor.-Am. 1. p. 122. /. 42 ; Torr. <^ Gr. fl. N. Am. 1. p. 262. 

 R. franguloides, Michx. fl. \.p. 153; Pursh, fl. I. p. 166? 



