PEA AND BEAN TRIBE. 139 



1. EHAMNUS (Buckthorn). 



E. cathdrticus (Common Buckthorn). Branches ter- 

 minating in thorns ; flowers 4-cleft, dioecious (stamens 

 and pistils on separate plants) ; leaves egg-shaped, 

 sharply serrated ; berry 4-seeded. A spreading shrub 

 with dense branches of small green flowers, which are 

 succeeded by black, powerfully cathartic berries. These, 

 if gathered before they are ripe, yield a yellow dye ; 

 when ripe, they form, if mixed with gum-arabic and 

 lime-water, the green colour known under the name of 

 Bladder-green. Woods and thickets. Fl. May. Shrub. 



E. Frdngula (Alder Buckthorn). Branches without 

 thorns ; flowers 5 -cleft, all perfect ; leaves entire, smooth ; 

 berry 2-seeded. A rather slender shrub, 6 10 feet 

 high, with smooth blackish branches, deep green leaves, 

 and small greenish flowers, which are not so densely 

 tufted as in the last. Woods and thickets. Fl. May. 

 Shrub. 



ORDER XXV. LEGTJMINOS^E. PEA AND BEAN 

 TRIBE. 



Calyx 5-cleft, with the odd lobe in front ; petals 5, 

 papilionaceous ; stamens 10, their filaments either united 

 into a tube, or forming 2 sets of 9 and 1 ; ovary, style, 

 and stigma, single ; seed-vessel a 2-valved, sometimes 

 imperfectly jointed pod, or legume ; seeds on the upper 

 seam of the pod-valves. A highly interesting order of 

 plants, containing as many as 6,500 species, which vary in 

 size from minute herbs to vast trees with trunks upwards 

 of 80 feet in circumference. In structure, properties, 

 colour of flowers, and range of growth, they vary scarcely 

 less than in dimensions ; they are found in all parts 

 of the known world, except St. Helena and another 

 remote island ; many species, under the general name of 

 pulse, afford most nutritious food for example, Peas, 



