WORMSEED 071 



0.040 mm. in diameter. On adding the powder to water the latter 

 becomes a pale straw-color. 



Constituents. Volatile oil; an amorphous bitter principle; 

 a gummy substance, calendulin, which forms with water a transparent 

 mucilage that is not precipitated by tannin; and resin. 



Allied Plants. The florets of various Composite are sometimes 

 admixed with or substituted for Calendula, of which the following 

 may be mentioned together with their principal distinguishing char- 

 acteristics (Fig. 294). The ligulate corolla of Taraxacum officinalo 

 is 5-toothed; the ligulate corolla of Arnica montana is 7- to 12-veined; 

 the ligulate corolla of Tussilago Farfara is linear, about 13 mm. in 

 length and about 0.3 mm. in breadth, summit acute, entire; and tho 

 ray florets of Tagetes patula are somewhat spatulate, about 20 mm. 

 in length and 10 mm. in width, sometimes marked with darker stripes, 

 and have undulate margins. 



SANTONICA. Levant Wormseed. The flower-heads of Arte- 

 misia Cina (Fam. Compositse), a small shrub indigenous to the deserts 

 in Russian Turkestan. In recent years the Russian Government has 

 divided the region bounded on the east by the mountain chain of the 

 Kara-tau, and on the west by the river Syr Darja, into 5 districts, and 

 leased the right of collection for 1 year to the highest bidder in public 

 auction. The flower-heads are collected in July and August before 

 they expand, and carefully dried and preserved. If the flower-heads 

 are unexpanded and quickly dried they will yield over 3 per cent of 

 santonin; just so soon as the flower matures, however, there is a rapid 

 disappearance of the anthelmintic principle. 



Description. Oblong or ellipsoidal, 2 to 4 mm. in length, 1 to 1.5 

 mm. in diameter; involucre ovoid, consisting of twelve to eighteen 

 closely imbricated, ovate or ovate-lanceolate, glandular, somewhat 

 shiny bracts, about 2 mm. in length, with a yellowish-green or greenish- 

 brown middle portion and whitish margin; torus flat, naked, with 

 three to six unexpanded, perfect tubular flowers about 1.5 mm. in 

 length and completely inclosed by the upper bracts; ovary oblong; 

 pappus wanting; odor distinct; taste aromatic. 



INNER STRUCTURE. See Fig. 295. 



Powder. Light brown; pollen grains spheroidal from 0.015 to 

 0.020 mm. in diameter, nearly smooth and having 3 pores; glandular 

 hairs of two kinds, either with 1 or 2 short cells or with 2 to 3 pairs of 

 cells. If a few c.c. of an alcoholic (95 per cent) extract of santonica 

 is heated with a few drops of potassium hydrate solution, a reddish 

 color is produced. 



Constituents. A crystalline neutral principle, santonin, which 



