POWDERED DRUGS. 
281 
striate, one kind with acute end cell and the other 
with rounded end cell ; secretion hairs either six to 
eight-celled in a double row, and glandular head two- 
celled, or short stalked and glandular head four to 
twelve-celled ; pollen grains ellipsoidal, 10 to 20 // in 
diameter and with numerous centrifugal projections; 
pappus a multicellular axis about 30 n in diameter, 
with short unicellular alternate branches; ducts spiral, 
annular, or with bordered pores ; sclerenchymatous 
fibers thin walled, non-lignified, with few, simple 
oblique pores. 
25. Grindelia. — Light green ; ducts spiral, annular, 
or with bordered pores, strongly lignified ; scleren- 
chyma fibers thin-walled, non-lignified, with numerous 
simple more or less oblique pores ; pollen grains 
spherical, about 25 jjl in diameter, with numerous 
centrifugal projections; secretion hairs depressed, 
globular, multicellular ; numerous oil globules and 
resin masses; pappus a multicellular axis with minute 
teeth . 
P FRAGMENTS OF PAPPUS WANTING. 
26. Digitalis. — Dark green ; non - secretion hairs 
simple, consisting of two to five superimposed cells, 
straight or slightly curved ; secretion hairs with one- 
celled stalk and one to two-celled glandular head ; 
stone cells, star-shaped hairs and calcium oxalate 
crystals are wanting. 
27. Hedeoma. — Dark green; non - secretion hairs 
slightly curved, two to three-celled, thick-walled, with 
numerous slight centrifugal projections ; secretion 
hairs with one celled stalk and eight-celled glandular 
head; pollen grains somewhat spherical, about 35 yu. 
in diameter, nearly smooth ; ducts spiral, with simple 
and bordered pores; sclerenchymatous fibers long, 
thin-walled, lignified, with numerous simple pores ; 
