ARNICA 667 



glandular and pubescent below, ovary about 6 mm. in length, glan- 

 dular and pubescent; achene spindle-shaped, dark brown, finely 

 striate, glandular-pubescent and surmounted by a pappus (Fig. 293) 

 of white barbed bristles about 7 mm. in length; odor distinct; taste 

 bitter and acrid. 



Powder. Yellowish-brown; pollen grains spheroidal, from 0.025 

 to 0.035 mm. in diameter, having 3 pores and a cuticle with numerous 

 spinose thickenings; non-glandular hairs of three kinds: (a), either 

 unicellular; (6), uniseriate, 5- to 6-celled, or (c), consisting of a pair 

 of united unicellular hairs with numerous pores on the dividing wall; 

 glandular hairs of three kinds: (a), either with a large unicellular 

 stalk and unicellular glandular head; (6), with a stalk of a single row 

 of 4 cells and a 1-celled glandular head; or (c), a stalk of a double 

 row of 5 cells and a 2-celled glandular head; pappus consisting of a 

 multicellular axis with unicellular branches (Fig. 293). 



Constituents. A bitter crystalline principle, arnicin, about 4 

 per cent ; and volatile oil 0.04 to 0.07 per cent, consisting of a butyra- 

 ceous substance. 



Adulterants. Arnica flowers are not infrequently adulterated 

 with the flowers of various other Compositse, or even entirely sub- 

 stituted by them; of these may be mentioned the flowers of Calendula 

 officinalis (see Calendula) ; species of Inulu, the achenes of which are 

 glabrous; and Tragopogon pratensis, the ligulate florets of which 

 are 5-toothed at the summit (Fig. 294). 



The flowers of Inula britannica are smaller, the ligulate flowers 

 are 4-veined, the receptacle is smooth and the achene is about 1 

 mm. in length. (U. S. Dept. Agric.) 



ANTHEMIS. Roman or English Chamomile. The expanded 

 flower-heads of Anthemis nobilis (Fam. Compositse), a perennial 

 herb indigenous to southern and western Europe and cultivated in 

 Belgium, England, France, Germany, Hungary and the United 

 States, and naturalized from Rhode Island to Michigan and south to 

 Delaware. The flowers are collected from cultivated plants, and 

 dried by artificial means, the principal supplies coming from Belgium, 

 France and Saxony. 



Description. Globular, compressed, 1.5 to 2 cm. in diameter; 

 involucre hemispherical, with two or three rows of imbricated, nearly 

 equal, somewhat elliptical, very pubescent scales, having a greenish 

 middle portion and a yellowish margin; torus conical or convex, 

 solid, 3 to 4 mm. in height, occasionally hollow, and sometimes con- 

 taining the larvae of an insect; chaff-scales resembling the involucral 

 scales, about 2 mm. in length; ligulate florets numerous, 6 to 10 mm. 



