GENERAL INDEX 



311 



Oils, 5 ; antiseptic, 136 ; fixed, 142 ; 



as a food-reserve, 146, in seeds, 



147 ; volatile, 143, 151 ; in xero- 



phytes, 42 

 Oily seeds, 148 

 Old man's-beard, 217. See Clematis 



Vitalba 

 Olive, 23 

 Onion : bulb, 150 ; bulbils, 160 ; inn.. 



181 ; seeds, *146 ; sugar, 146, 150 

 Ononis arvensis, spines, 44 

 Open associations, 277 ; habitats, 16 

 Opium, 143, 152 

 Orange, 23 

 Orchid : bird's-nest (see Neottia) ; 



coral-root (see Corallorhiza) ; fr., 



189; honey, 173; inn., 180; 



pollination, 177 ; seed, 195 ; 



tubers, 111 

 Origin of species, 202 

 Orobanche, 127 

 Orobus, fr., *189 

 Osier-beds, 244 

 Osmosis, 25, 91 

 Ovary, 162, 183 

 Ovule, 162 

 Oxalis, 62 ; aril, 196 ; cleistogamous 



fls., 165 ; fr., 189 ; oxalic acid in, 



143 ; rhizome, 154 ; seeds, 196 ; 



sleep-movements of leaves, 70, 



*71. See Sorrel 

 Oxtongue, 60, 217. See Helminthia 



echioides 

 Oxygen, 6, 7 ; in air, 78, 79 ; in 



water, 48, 50 ; in soil, 88 



Pseony, 168 



Palisade-tissue, 41, *72 



Palm, 23 ; -oil, 148 



Pampas, 20 



Panicle, 178, 179 



Panicum miliaceum, 147 



Papaver somniferum, alkaloid of, 



143, 152 

 Pappus, 195 

 Parasites, 6, f!25, 206 ; partial, 126 ; 



total, 126 ; hemi-parasites of 



meadow-land, 263, of natural 



pasture, 257 



Parallel development, 105 

 Parietaria officinalis, fls., 177 

 Paris quadri folia, 214 

 Park-land, 17, 126 

 Parsley, 181 

 Parsnip, 150 

 Partial parasites, 126 ; saprophytes, 



125 



Passion-flower, tendrils, *118 



Pastures, 15, 18, 20 ; alpine, 230, 

 251, 259 ; artificial, 20, 261, weeds 

 of, 264 ; limestone-, 230, 259 ; 

 lowland-, 230, 258 ; natural, 257 ; 

 sub-alpine, 230, 258 



Pea : fr., 188 ; pollination, 165 ; 

 protein of, 147 ; root-nodules, 95 ; 

 seeds, 146, 195 ; tendrils, 118. 

 See LatJiyrus 



Peach : fr., *192 ; origin of, 205 



Pear : bud-scales, 61 ; cultivation of, 

 149 



Peat, 17, 83, 93, 94, 244, 248, 254 ; 

 absorptive power of, 87 ; -bogs, 

 246, 248, xerophytic factors of, 

 35 ; moorland-, constitution of, 

 249, comparison with marsh-peat, 

 249, conditions necessary for 

 formation of, 248 ; water-capacity 

 of, 87. See Humus 



Pedicularis, 59 ; parasitic nature, 

 126 



Pelargonium : fr., 190, 195 ; infl., 181 



Pellitory. See Parietaria officinalis 



Pennyeress, 216 



Pepper, 151 ; -mint, 151 



Percolation in soils, 87 



Perennating organs, 62, 109 ; struc- 

 tures, f62 



Perennials, 108 ; evergreen, 109 ; 

 herbaceous, 109, 115, 145 ; tropo- 

 phytic, 59 ; xerophyticj 59 



Perianth, f!62 



Pericarp, 183 



Permeability of soils, 87 



Peruvian bark. See Cinchona 



Petals, 162 



Petioles : of Acacia, 43, *44 ; of float- 

 ing aquatic leaves, 51 



Phaseolus vulgaris, twiner, 116. See 

 Scarlet runner. 



Phleum arenarium, 60 



Phloem, *45 ; in aquatics, 49 



Phormium tenax, 42 



Photosynthesis, f4, 66, 78 



Phragmites, 62 ; -associations, 242, 

 245 



Phylloclade, 44, *45 



Phyllode, 43, *44, 46 



Physical action of water on rocks, 

 81 ; properties of soil, 85 



Physiognomic groups, 16 



Physiological dryness, 34, 85 



Physiology, f!03 



Pillwort. Ses PiMaria 



PiMaria, 28, 50 



