396 BOTANY AND PHARMACOGNOSY. 



rounded or conical torus, which is about 12 mm. in diameter and 

 2 or 3 series of lanceolate, obtuse, involucral scales. The ray- 

 florets are pistillate, the corolla varying in length from i to 2 cm. 

 and having numerous delicate veins and 3 short, obtuse or rounded 

 teeth. The tubular flowers are perfect and about 6 mm. long. The 

 ovary is 5-ribbed and the pappus forms a short, toothed crown. 

 The odor is distinct and the taste bitter. 



Persian Insect Flowers are derived from C. roseum and C. 

 Marshallii, growing in the Caucasus region, Armenia and North- 

 ern Persia. The heads are about the same size as those of C. 

 cinerariifoliuni; the torus is dark brown ; the involucral scales 

 and ray-florets are purplish-red; the ovary is lo-ribbed. 



Insect flowers contain from a trace to 0.5 per cent, of a vola- 

 tile oil, the Persian flowers containing the larger proportion, and 

 the amount decreasing with the maturing of the flowers. They 

 also contain two resins, varying from 4 to 7 per cent., the larger 

 amount being found in the Dalmatian flowers; a small quantity 

 of a glucoside and a volatile acid. 



While it is claimed that the insecticidal efifects of insect pow- 

 der are due to a mechanical action in closing the breathing pores 

 of non-biting insects, it is probable that they also have a toxic 

 action, due to some poisonous principle, which apparently may 

 be extracted with alcohol and applied in solution. 



Wormwood or Absinthium consists of the dried leaves and 

 flowering tops of Artemisia Absinthium, a perennial, somewhat 

 woody, branching herb, indigenous to Europe and Northern 

 Africa, cultivated in New York, Michigan, Nebraska and Wis- 

 consin and naturalized in the United States from plants that have 

 escaped from cultivation. The leaves are grayish-green, gland- 

 ular-hairy, I- to 3-pinnately divided, the segments being obovate, 

 entire, or lobed ; the flowers are yellowish-green, the heads being 

 about 4 mm. broad and occurring in raceme-like panicles; the 

 torus is hemispherical and the involucre consists of several series 

 of linear bracts, the inner being scale-like; the florets are all 

 tubular, the outer ones sometimes being neutral. The herb is 

 aromatic and very bitter. 



The fresh drug contains about 0.5 per cent, of a volatile oil 

 which is of a dark green or blue color, has a bitter, persistent taste 



