INDEX 



417 



Perennial herbs, in arctic coun- 

 tries 25. 



Peridineae, constituents of 

 phyto-plankton 157. 



Pernettya empetrifolia, in Falk- 

 land Isles fell-field 260. 



Persian salt-desert 234. 



Peruvian loma, vegetation 287. 



Pes-caprae-association 227. 



Petrophytes 240. 



Phormium tenax, growing on 

 wet and dry soils 194. 



Photometric movements, of 

 leaves 19. 



Photophilous (heliophilous) 

 plants, characters 18. 



Phrai^mites communis 233 ; in 

 reed-swamp 187, 189; in sudd- 

 formation 189; travelling geo- 

 phyte 9. 



Phyllodoce caernlea 257. 



Phyllodoce-association, in 

 Finland 214. 



Physiognomic systems 4, 5. 



Physiognomy, factors influenc- 

 ing 25 ; of vegetation, circum- 

 stances determining 137. 



Physiological, dryness, of soil 

 49. 50. 56- saline 223, wet 195 ; 

 races, of parasites 85. 



Phyto-plankton 155. See also 

 Plankton. 



Picea excelsa, as creeping shrub 

 215 ; as migrating species 364 ; 

 scrub-plant in Lapland 72 ; in 

 spruce- forest 313. 



Pigments, in alpine species 255. 

 See also Colours of flowers. 



Pinares, of Canary Isles, vege- 

 tation 315. 



Pine-forest (Pinetum) 312. 



Pines (Pineta) in woodland- 

 swamp 191. 



Pinetum, varieties 313; vege- 

 tation 312. 



Pinheiros, of Brazil 316. 



/Vj-, in dune-forest 268; species 

 of, growing on both wet and dry 

 soils 194. 



P. canartensis 315. 



P. Cembra, as creeping shrub 

 216. 



P. halepensis 315. 



P. montana, in forest at high 

 altitudes 216; in Pyrenees and 

 French Alps 314. 



P. Pttiea 315. 



P. sylvestris, in birch-forest 334; 

 as creeping shrub 215 ; in pine- 

 tum 312. 



P. Taeda, growing on wet and 

 dry soils 194. 



Piperaceae, as epiphytes 88. 



Pistacta, in Mediterranean flora 



.^04- 

 Placoditim mtirale, on shore 

 rocks 224. 



WARMING 



Plank-buttress roots, of trees 

 in tropical rain-forest 342. 



Plankton, 152, 154; .adapta- 

 tions 157; composition 159; 

 distribution 157, 160; false 

 160; flora 155; flotation- 

 devices 158 ; foul-water 162 ; 

 neritic 160 ; oceanic 161 ; 

 power of flotation 157 ; quan- 

 tity 159 ; salt-water 160 ; 

 seasonal changes 159 ; sub- 

 formations 160 ; tycholimnetic 

 160 ; as ultimate source of food 

 159. See also Phyto-plankton. 



Plankton-formation 155. 



Plant-associations, see Asso- 

 ciations. 



Plant-communities 91 ; classi- 

 fication 131 ; definition 12, 13; 

 distribution, influenced by angle 

 of incidence of sun's rays 51, 

 influenced by direct sunlight 51 ; 

 dominant and sub-dominant 

 species 139; importance of soil 

 in determining 132 ; struggle 

 between 348, 358. See also 

 Communities. 



Plant-community, discussion 

 of term 91. 



Plant-form, influence of snow 

 72. 



Plant-geography, definition 1 ; 

 floristic, scope i ; oecological, 

 scope 2. 



Plant-physiognomy, in rela- 

 tion to landscape, significance 4. 



Plantago major, rosette-plant 



9- 

 P. tnarttima 231. 



Plants, and animals, relations 

 between 83. 



Platycerium aUicorne, pocket- 

 leaves 89 ; in tropical rain- 

 forest 341. 



Platysma-heath, composition 

 208. 



Pleuston, associations and dis- 

 tribution 166 ; adaptations 165 ; 

 characters 164; flora 164. 



Plocama pendula, in Canary 

 Islands 279. 



Plumbaginaceae, hydathodes 

 103. 



Pneumatophores, in mangroves 

 186; in marsh-plants 186. 



Poa, in meadow 323, 324, 325. 



P. a/ueps, in tussock formation 

 199. 



P.Jlabellata, in tussock-formation 

 200. 



Pocket-leaves, of epiphytic 

 ferns S9. 



Podostemaceae 167, 168, 169. 



Pollen-mud 65. 



Polycarpic plants, relations 7 ; 

 groups 8. 



Polygonum eqiiisctifortne 276. 



E e 



Polypodiumqnercifolium,'pockei- 

 leaves 89. 



Polytrichum 2ir, 212; in pro- 

 duction of sand-dunes 265. 



P. septentrionale 258. 



Polytrichum-kar 208. 



Pontic (Pannonian) hills, waste 

 herbage 290. 



Po-ophytes 135. 



Potamogeton crispHs, hiberna- 

 cula 183. 



Potamo-plankton 161. 



Prairie, approximating to 

 meadow 325; associations 

 286 ; oecology 286 ; origin and 

 vegetation 285. 



Prairie-fires 353, 



Prairie-grass, association 286. 



Prairies 281. 



Primeval forest 339. 



Primula acaulis, flowers formed 

 under snow 252. 



Prop-roots, of mangrove-plants 

 236; oi Pandanus 342 ; of trees 

 in tropical rain-forest 342. 



Proteaceae , in Australian shrub- 

 steppe 281. 



Protection, of plants, against 

 animals 83. 



Psamtna ( Ammophila) arenaria 

 109; deep-growing roots 268; 

 importance as dune-grass 264 ; 

 in inland districts 263 ; in pro- 

 duction of high dunes 264, 



Psammeta 264. 



Psammogenous rocks 69. 



Psammophilous, forest, tropical 

 littoral 272; halophytes 223, 

 262, zones 225. 



Psammophjrtes 136, 262 ; for- 

 mations 262 ; oecological fac- 

 tors 263. 



Pseudo-maqui 307. 



Psilophytes 136, 293. 



Psiloturn Jlaccidum, in tropical 

 rain- forest 341. 



Psychrophytes 136, 248. 



Pleris aquilina, in evergreen 

 coniferous forest 311; in fern- 

 heath 292; in tjemoro-forest 

 of Java 300 ; travelling geo- 

 phyte 9. 



Pterocaulon vesuvianum, on lava 

 241. 



Piinas, of the Andes 253, 261. 



Pusztas, of Hungary 2S3. 384. 



Pygmy-trees, in tropical fcU- 

 field 260. 



Pyrenees, Rhododcndron-bush- 

 land on 215; Pinus montana on 

 216. 



Pyrola 311. 



Qiicrcus, in Mediterranean oak- 

 forest 308 ; in oak-forest 333. 

 Q. Ilex, in maqui 306. 

 Q. Sttbcry in Algeria 309. 



