NOTES AND OBSERVATIONS. 149 
4. A COLORING MATTER FOUND IN SOME BORRAGINACEAE. 
BY J. B. 8. NORTON. 
Some time last summer Mr. J. G. Smith, of the Division 
of Agrostology, sent a small specimen from Grant Co., 
New Mexico, to the Missouri Botanical Garden for identifi- 
cation, which I decided to be Plagiobothrys Arizonicus 
Greene. Mr. Metcalfe, who collected the plant, says that 
‘¢when the sheep find a patch of it, it colors their heads 
red clear to their ears.’’ The herbage of the dried plant 
had stained the letter which unclosed it a violet purple, 
something like wine stains. Mr. A. M. Ferguson tells me 
that a plant of western Texas, doubtless also some species 
of Borraginaceae, is known to affect sheep in a similar 
manner. The New Mexican plant is known there as blood 
purslane, says Mr. Smith in a recent letter, and is fine for 
sheep pasture in the spring. 
These facts prompted me to further investigate the 
matter. I examined the other specimens of the same 
species and others of that genus and related genera in the 
Garden herbarium and found that a number of specimens 
had stained the paper in the same way, some through as 
many as five herbarium sheets. The color spreads through 
the paper from the mounted plant, though in what manner 
I have not been able to ascertain. 
It is well known that a coloring matter is common in the 
roots of several species of Borraginaceae and the substance 
is probably the same in all. It is known as alkannin, and 
is a non-nitrogenous, resinous, purple coloring matter, 
soluble in oils, alcohol and ether but not soluble in water.* 
alkannin or alkanet (or alcanet), as the dye is called, is 
* The information regarding the properties and uses of alkannin is 
taken from Tschirch, Angewandte Pflanzenanatomie, The United States 
Dispensatory, and The Century Dictionary. 
