INDEX 
46S 
Operculum, 287 
Ophioglossales, 3 
Opium, 94, 333 
Optical combination, 32 
Opuntia, 370 
Opuntiales, 370 
Orcein, 282 
Orchid family, 305 
floral organs of, 307 
Orchidaceae, 305 
Orchideae, 307 
Orange, fruit of, 210 
Order, 2 
Orders, naming of, 7 
Ordinary Parenchyma, 101 
Oregon balsam, 295 
Organs, essential, 181 
plant, 121 
reproductive, 121 
vegetative, 121 
Origanum, 397 
majorana, 397 
vulgare, 397 
Oscillatoria, 228, 229 
Osmic acid, 23 
Ostwald, 94 
Ourouparia Gambir, 398 
Outline of plant groups, 3, 4 
Ovary, 195 
Ovule, amphitropous, 197 
anatropous, 197 
campylotropous, 197 
immature angiospermous, Fig. 
of, 201 
matured embryo sac in angio¬ 
spermous ovule, Fig. of, 
201 
orthotropous, 197 
shape of, 197 
Ovules, 195 
defined, 196 
in angiosperms, 196 
in gymnosperms, 196 
position of, 196 
30 
Ovum, 43 
Oxytropism, 64 
Pachistima, 356, 357 
Palaquium, 380 
Palm cocoanut, 299 
Date, 299 
Family, 299 
oil, 300 
Palmeae, 299 
Panax quinquefolium, 376 
repens, 376 
Pandorina, 232 
Panicle, 179 
Pansy, papillae on epidermis. to8 
Papaver, 332 
latex of, 94 
placentation in, 197 
somniferum, 333 
Papaveraceae, 332 
Papaverales, 332 
Papain, 96, 369 
Papaw, 96, 369 
Papaw Family, 369 
Papilionaceae, 341, 342 
Pappus, 202 
Paprika, 391 
Papyrus, 409 
Paraphyses, 245, 256, 286 
Parasite, 247 
Pareira, 328 
Parenchyma, 101 
assimilation, 101 
conducting, 101 
ordinary, 101 
phloem, 101 
reserve, 103 
wood, 101 
Parietales, 366 
Parmelia, 282 
Parsley Family, 377 
Passiflora, 183, 369 
Passiflora N. F., 369 
incarnata, 369 
