196 



HERBS 



Description. The plant produces, usually in its second year, an 

 erect, cylindrical, glabrous, hollow stem, reaching a height of 1*5 to 

 2 metres, the lower part of which bears purplish spots which, however, 

 usually disappear on drying. 



The leaves are dark green on the upper, paler on the under surface, 

 quite glabrous, and attached to the stem by ainplexicaul petioles. 

 The lower are large and decompound, attaining 50 cm. in length, the 

 upper being less divided ; the ultimate segments are ovate or lanceolate, 

 and acute, terminating in smooth, colourless, horny points (fig. 105, a). 



The umbels are about twelve-rayed, and provided with both general 

 and partial involucres, the latter consisting of three short, lanceolate 

 bracts directed outwards. The fruits are broadly ovate and 



. 105. Portion of leaf of a, Oonium maculatum ; 

 6, Anihriscus sylv&stris ; c, jEthusa Gynapium. Mag- 

 nified 2 diam. (Vogl.) 



characterised by the irregular, crenate ridges and grooved endosperm. 

 (Compare ' Hemlock Fruits.') 



The plant has a bitterish taste and unpleasant odour, especiaUy 

 when crushed ; the addition of solution of potash produces a strong, 

 disagreeable odour of mice. 



The student should observe 



(a) The glabrous, spotted hollow stem, 



(b) The much divided leaves, which are paler on the under 



surface, quite glabrous, the ultimate divisions terminating 

 in smooth colourless points, 



(c) The general and partial involucres, 



(d) The crenate ridges and grooved endosperm of the fruit. 



Constituents. Hemlock herb contains coniine and conhydrine. 

 These alkaloids are present in both stem and leaves in largest quantity 

 when the plant is in full flower, the stem then containing 0-064 per 

 cent., the leaves 0-187 per cent., and the flowers and flower-stalks 



