292 
PHARMACEUTICAL BOTANY 
ORDER 1 .—FIL1CALES OR TRUE FERNS (HOMOSPOROUS) 
Family Polypodiaceov. —Sporangia with annulus vertical and 
incomplete. 
The rhizomes and stipes of Dryopteris filix-mas and Dryopteris mar- 
ginalis are official in the U. S. P. The fibro-vascular bundles of 
these are concentric in type but differ from the concentric fibro- 
vascular bundles of some monocotyledons in that xylem is inner¬ 
most and phloem surrounds the xylem. 
Pig. 159. —Cyrtomium falcatum. Under (dorsal) surface of a portion of a 
sporophyll, showing the numerous sori on the pinnae. (Gager.) 
ORDER 2.— HYDROPTERALES OR WATER FERNS 
(HETEROSPOROUS) 
Family Salviniacea. Floating ferns with broad floating leaves and 
submerged dissected leaves which bear sporocarps. Examples: Sal- 
vinia and Azolla. 
DIVISION IV.—SPERMATOPHYTA (PHANEROGAMIA) 
Plants producing real flowers and seeds. The highest evolved 
division of the vegetable kingdom. 
SUBDIVISION I.—GYMNOSPERMVE—THE GYMNOSPERMS 
The Gymnosperms comprise an ancient and historic group of seed 
plants which were more numerous in the Triassic and Carboniferous 
