282 
PHARMA COG NOSY. 
epidermal cells with sphere -crystals or irregular 
masses of a carbohj^drate. 
28. Marrubium. — Dark green; non - secretion hairs 
much twisted, one to seven-celled, thin-walled, smooth, 
frequently arranged in groups of about six or eight, 
and spreading from the base; secretion hairs with one- 
celled stalk and eight-celled glandular head ; pollen 
grains spherical, about 25 n in diameter, and with 
numerous centrifugal projections ; ducts spiral, annu- 
lar, or reticulate, slightly lignified ; sclerenchymatous 
fibers thin-walled, non-lignified, and with few simple 
pores. 
29. Mentha Piperita. — Dark green ; non-secretion hairs 
one to eight-celled, thin-walled, with numerous slight 
projections ; secretion hairs two kinds, one or three- 
celled stalk and one or eight-celled glandular head ; 
pollen grains somewhat spherical, smooth, about 35 n 
in diameter; ducts spiral, or with simple and bordered 
pores and slightly lignified ; sclerenchymatous fibers 
thin-walled, non-lignified, with numerous oblique pores. 
30. Salvia. — Dark green ; non-secretion hairs one to 
six-celled, filled with air; secretion hairs numerous, of 
two kinds, stalks one to three celled, glandular heads 
unicellular or eight-celled. 
b. Secretion Hairs Wanting, 
a WITH NON-SECRETION HAIRS. 
31. Lobelia. — Dark green ; non-secretion hairs one- 
celled, 03 to 06 mm. long, walls moderately thick, 
with numerous slight centrifugal projections; pollen 
grains ellipsoidal, smooth, 15 to 30 n in diameter; 
laticiferous vessels branched ; ducts spiral, scalariform 
and with bordered pores; sclerenchymatous fibers 
comparatively thin-walled, non-lignified, and with 
simple oblique pores. 
