160 LACTUCA YIROSA 



neck below the pappus. Fruit oval,, strongly compressed, with a 

 broad wing along the edge and 8 slender ribs on each face, rough, 

 almost black, prolonged above into a white beak as long as itself, 

 expanded at the top and carrying the spreading silvery pappus, 

 hairs simple, denticulate. 



Habitat. This kind of Wild Lettuce is not uncommon in Eng- 

 land, especially in the south-eastern counties, growing in hedges 

 and on banks, where its large radical leaves are very conspicuous ; 

 the flowers, which appear in August, are only fully expanded in 

 the morning sunshine. The plant grows also throughout western 

 and southern Europe, and extends eastwards to Western Siberia. 



The whole plant is traversed by milk-vessels, and the slightest 

 puncture, especially of the young branches or involucral scales, 

 causes an instant copious outflow of the white latex, which on 

 exposure soon becomes brown and solid. 



Syme, E. Bot., v, p. 145; Hook, f., Stnd. FL, p. 214; Watson, 

 Cyb. Br., p. 210; Gren. & Godr., Fl. France, ii, p. 320; 

 Ledebour, Fl. Ross., ii, p. 805; Lindl., Fl. Med., p. 469. 



Official Part and Name. LACTUCA, Lettuce ; the flowering herb 

 (B. P.). The flowering herb (I. P.). It is not official in the 

 Pharmacopoeia of the United States ; its place being there taken 

 by the Garden Lettuce, Lactuca sativa, L. 



General Characters and Composition. The whole herb, espe- 

 cially during the period of flowering, abounds in a white milky 

 juice, which instantly exudes when the plant is wounded. This 

 juice has a bitter taste, and a strong opiate-like odour. When 

 the juice is excluded from the air in closely-stopped bottles it 

 undergoes little change ; but when exposed to the air it quickly 

 hardens, and assumes a brownish colour, and then constitutes what 

 is termed lactucarium. This substance is described by us under 

 " Lactuca sativa," which is also one of its sources. Lactucarium is 

 official in the Pharmacopoeia of the United States, but its place is 

 supplied in the British Pharmacopoeia, and in the Pharmacopoeia of 

 India, by the extract of Lettuce, which is directed to be prepared 

 from the species of Lactuca now under description. 



