BOTANIC MATERIA MEDICA, 103 
3 feet. The rhizomous root is fleshy and thick, 
especially about the annual joints, and bears 
upon its under surface numberless rootlets; the 
joints are from % to &% inch apart; the lower 
half of the root is much annulated and has a 
circular scar at the upper portion; in fact, the 
root is annulated by the scars of the previous 
leaves—from the years of growth gone by. The 
recent root is almost devoid of odor, but has an 
acrid, nauseous taste. There are said to be five 
varieties, besides the one mentioned: Iris Vir- 
ginica, or slender blue flag; Iris Cuprea, found 
in the South and far West; the Iris Verna, or 
dwarf Iris, and the Iris Lacustris, Lake dwarf 
Iris, found on the shores of Lake Michigan. 
The blue flag contains resin, fat, sugar, gum 
and ¢annin, and an active principle called Irisin. 
Blue flag is alterative, diuretic, emetic and pur- 
gative, and given in doses of 5 to 15 grains (0.3 
to 1.0 gram) in powder. The officinal prepara- 
tions are the extract and fluid extract, the dose 
of which is 3 to 4 grains of the former and ro to 
30 drops of the latter several times a day, ac- 
cording to the will of the prescriber. Blue flag 
is by no means a popular remedy; whilst it has 
many virtues, it has obtained a doubtful renown 
_ from the fact that it has been used by unprin- 
cipled schools of medicine. It is rarely found 
in the stores except in form of the officinal prep- 
arations, and occasionally in form of so-called 
resinoid, which is an oleoresin obtained by pre- 
cipitating a strong alcoholic tincture, much used 
by the school termed ‘‘ Eclectics. Ce 
Leptandra, Leptandra, Leptandra Virginica. 
—Natural order Scrophulariacee. Commonly 
