6 BULLETIN 795, U. S. DEI'AUTMEXT OF AGRICULTURE. 



Table 3 gives a comparison of analyses of the different commercial 

 grades of insect flowers ("open" and "closed") and insect flower stems 

 with those of the floAvers of C. Leucantliemum. The averages of all 

 determinations are compared for each constituent. 



The results in Table 3 show that the greatest differences in the 

 chemical composition are in the phosphorus, ash, and pentosans, 

 which are higher in the flowers of C. LeucantJiemuin than in those of 

 G. cinerariwfoliuDi. It is evident, however, that a' chemical analysis 

 alone is insufficient to show adulteration of insect powder with pow- 

 dered daisy flowers. Such adulteration can be definitely determined 

 only by microscopic examination. 



MORPHOLOGY OF CHRYSANTHEMUM LEUCANTHEMUM. 



The daisy plant is a typical Composite. It is a perennial witli 

 nearly smooth stem, growing to a height of from 1 to 3 feet, and 

 sparingly branched. The leaves are coarsely cut, the uppermost leaves 

 being smaller than the lower ones and nearly 'entire. The flower heads 

 consist of white ray flowers and yellow disc flowers. The iuvolucral 

 bracts are lanceolate, nearly smooth, with a narrow, chestnut-brown 

 margin. The fruit, when mature, consists of very small achenes, 

 with a black background and conspicuous white ribs running length- 

 wise of the fruit. There is usually' a small tubercle or knob-like pro- 

 jection on the broad end, apparently the remains of the flowers. (PL I, 

 fig. 2.) 



Beringer (2) and Vogtherr (39) go quite into detail in a morpho- 

 logical description of field daisy flowers. 



Field daisy floAvers (Recurring in insect flowers are much more easily 

 detected than when in powdered form. The most positive character 

 that can be relied upon for their detection is the fruit. Even in 

 an immature condition the fruit of the daisy does not resemble that 

 of Clirjjsanilietnuni cincrariccfoliinu. The following compilation is 

 given to serve as an aid in distinguishing between the fruits of C. 

 cineraria'folhoit and those of C. Leuccnithcinum (PL I, figs. 1 and 2). 



Dalmatian fioiccfs. — Achenes 5-ribbed; possess small-toothed crown; 

 golden j'Cllow in color; ray floret achenes more curved or arched than 

 the disc floret achenes (PL I, fig. 1). 



Daisy ffoiceis. — Achenes usually 10-ribbed; ribs very prominent, 

 white, alternating with black stripes ; tubercle or knob-like projections 

 on broad end of achene ; achene much smaller than that of the Dalma- 

 tian flower (PL I, fig. 2). 



HISTOLOGY. 



Schreuk (29) claims to have found a positively characteristic struc- 

 ture of daisy powder in the small, several-celled hairs which he de- 

 tected in considerable numbers on the apparently glabrous scales 



