Oak, 24 Oak forest, 53 Oat, 270 Obi, 232 Oil shales, 207 Olive, 48, 116, 251 Onions, 373 Opening of flowers, 76 Opium, 301 Opopanax, 114 Orange, 116, 243 Orchards, 252 Orchids, 78, 81, 330 Oxalis, 196 Painters and poets (botanists), 39 Palms, 69, 180 Pampas, 221 Paper (wood), 61, 62 Papyrus, 211 Parasitic insects, 294 " plants, 338 Pear, 188 " midge, 296 Peat, 170, 353 Peat-mosses, 353, 361 Pepper, 36 Perfumes, 73, 115, 119, 241 Petals, 98 Pfeffer, 88 Phragmites, 209 Phylloxera, 291 Pine forests, 40, 71, 148 Pine seeds, 41 Pineapple, 251, 277 Pink snow, 72 Pistacio, 69 Pitcher plant, 344 Plantain, 219 Plantations, 154 Plover, 298 Poisons, 226 Polar regions, 197 Pollen, 70 Polluted rivers, 208 Pomades, 119 Pondweeds, 205 Poppy, 263, 302 Potato, 279 Prairie, 220 Pressure inside plants, 25 Prickly pear, 243 Primula, 193 Protoplasm, 195 Quinine, 33 Rabbits, 50, 178, 182, 239 Radium rays, 21 Rafflesia, 337 Railway plants, 174 Rain of blood, 252 Rainwater (absorbed), 298 Raspberry, 92 Rattan, 47 Rat's-tail plantain, 93 Reeds, 163, 204, 209 Resin, 44, 45 Restharrow, 189 Retama, 137 Rhubarb, 36 Rimbach, 92 Roadside plants, 214 Robin-run-the-hedge, 313 Rock plants, 166, 169, 175 Rooks, 292 Roots, 86, 88, 89, 90, 137, 157, 180 Rose, 127, 182, 314 Rowan, 369 Rubber, 301, 310 Rushes, 203 Rye, 46, 272 Safflower, 34 Sago palm, 58 Saltwort, 161 Salvia, 78 Sandbox tree, 266 Sap, 23, 24 Sarracenia, 342 Satchell, 64 Savages and plants, 27 Scale insect, 288 Scenery and plants, 166 Schimper, 99 Scotch fir, 54, 71, 86, 360 Screes, 172 Scrub, 107 Scythian lamb, 32 Scythians, 224 Sea-grass, 162 Sea meadows, 162 Seaweeds, 163, 164, 171, 172 Season of flowers, 77 Sedges, 260 Selaginella, 56 Selection (principle of), 248, 277 Semaphore plant, 196 Senecio, 174 Sensitive plant, 14, 194 Sequoia, 47, 58 Shale, 173 Sheep-killing grasses, 267 Shelley, 79 Sherwood Forest, 53 Silvia Caledonica, 53 Silver fir, 58 Silurian times, 70 Smell (of flowers), 80 Smith, Dr., 54 Snow, 103 Soil, 82, 84 Solanaceæ, 234 Soldanella, 103 Solomon's seal, 94 Southernwood, 371 Speedwell, 319 Sphagnum, 357 Spice trade, 34 Spikenard, 367 Spines, 179, 186, 188, 190 Sprengel, 69 Spring, 98, 101 Squiers, 198 Squirrel, 178, 257 Stapelia, 80 Starch, 18 Starwort, 319 Steppes, 223 Sticky fruits, 255, 258 Sticky hairs, 347