4 o8 



229 ; (tjemoro-forest), occur- 

 rence and characters 300; 

 halophytes 221 ; shrubs, in 

 Egypto- Arabian desert 276; 

 stem, as xeromorphic adap- 

 tation 194. 



Aquatic, growth-forms 6 ; 

 plants, adaptations 96, forma- 

 tions 149, 154, hibernation 183, 

 vegetative propagation 183. 

 See also Hydrophytes. 



Aqueous tissue, in halophytes 



220. 



Arabian, Egypto-, desert 275. 



Araceae, as epiphytes 88. 



Araucaria brastliensis 316. 



Arctic, bushland, on acid soil, 

 characters 215 ; dwarf-shrub 

 heath 213; fell-field, associations 

 257, distribution and flora 257 ; 

 mat-grassland, flora 319 ; mat- 

 herbage, flora 319 ; mat-vege- 

 tation 318; regions, rarity of 

 annuals 251. 



Arctostaphylos 211. 



A. alpina 213. 



A . (7va-itrst, creeping plant 10. 



Argentina, chanar-steppe 280 ; 

 European species in 364 ; palm- 

 forest 347; salt-deserts 234; 

 sand-dunes, flora 271. 



Argentine, Andes, Lepidophyl- 

 lum-association 232, shrub- 

 steppes 261 ; pampas, salt- 

 steppe 232. 



Aristida, in prairie-flora 286. 



Arizona, shrub-steppe 280. 



Armeria maritima 231. 



Aromatic, shrubs, in maqui 

 306; substances in polar and 

 alpine species 255. 



Artemisia, in North American 

 shrub-steppe 278. 



A. frigida, in vermuth-steppe 

 278. 



A. maritima 231 ; in vermuth- 

 steppe 278. 



A. tridentata, in North Ameri- 

 can shrub-steppe 279. 



Arundinaria macrosperma, in 

 Dismal Swamp 190. 



Arundo Donax, in reed-swamp, 

 189. 



Asclepiadaceae, as lianes 91. 



Ash-forest 335. 



Asia, grass-steppe 285 ; moun- 

 tain-steppe 261 ; salt-steppe 

 232 ; sand-dunes 270; Central, 

 reed-swamps, composition 233, 

 salt tract 218, steppe 281 ; East- 

 em, meadow 325, parklands 

 325 ; and East Africa, similar- 

 ity of mangrove-plants 236. 



Asplenium Mffus, ' pocket- 

 leaves ' 89; in tropical rain- 

 forest 341. 



Association, definition 145; 



INDEX 



varieties, edaphic 146, geo- 

 graphical 146 ; terminology 

 145; Barringtonia- 228, 272; 

 buffalo-grass 286 ; Carex 



firma- 321 ; Coccoloba- 229, 

 272 ; Glyceria maritima- 230 ; 

 Nardns stricta- 321; Pesr 

 caprae- 227; prairie-grass 286. 



Associations 137, 144; abys- 

 sal saprophytic 176; arctic 

 fell-field 257 ; competitive, 

 complementary 95 ; comple- 

 mentary 368 ; deciduous dico- 

 tylous forest 331 ; dwarf-shrub 

 heath 212; lithophytes 242 ; 

 low-moor 197 ; moskar 208. 



Aster Tripolium 231. 



Asteriscus, see Odontospermum. 



Atmospheric, humidity, factors 

 influencing 30, as oecological 

 factor 28, saturation-deficit 30 ; 

 precipitations, adaptation for 

 absorption 31, distribution 34, 

 time 34. 



Atriplex 220, 226. 



A. portttlacoides 232. 



Atriplicetum 226. 



Australia, maqui 308; salt- 

 steppe 232; salt tract 218; 

 savannahs 299 ; sclerophyllous 

 forest 309, sclerophyllous vege- 

 tation 303 ; shrub-steppe, flora 

 280 ; virgin grassland 327. 



Australian forests, tree-ferns339. 



Avicennia, in mangrove- vege- 

 tation 235; respiratory roots 2 36. 



Azalea-heath 213. 



Azolla, relations with Anabaena 

 87. 



A zorella, a cushion-plant 116 ; on 

 Kerguelen 214 ; in South 

 American fell-field 259. 



A. caespitosa, in Falkland Isles 

 fell-field 260. 



Azorella-association, in Ar- 

 gentine Andes 261. 



Azores, maqui 307. 



Baccharis, in South American 

 fell-field 259. 



Bacteria,iron-sulphur- 223, 225; 

 nitrifying, in soil 79 ; in root- 

 tubercles of Leguminosae 80, 

 87 ; in soil, influence 79. 



Balkan Peninsula, sibljak 288. 



Baltic coast, natural pine- 

 forests 268. 



Bamboo-bushland, occurrence 

 2 95- 



Bamboo-forest, composition 

 191. 



Bamboos.in monsoon-forest 337. 



' Barren-ground,' of North 

 America 205. 



Barringtonia-association 228, 

 272. 



Batis maritima 232. 



Beech, in antarctic forest 338. 



Beech-forest 331 ; antarctic de- 

 ciduous 336 ; on mild humus- 

 5011332; onsour humus soil 333. 



Beggiatoa 174, 175, 176. 



Benthos 155 ; lithophilous, 

 adaptations 167, flora 167, 

 formations 169. 



Benthos of loose soil, factors 

 influencing 173; nature 154. 



Betula, in birch-forest 334. 



B. nana 211; in arctic bushland 

 2 1 5 ; in arctic dwarf-shrub heath 

 214 ; on wet and dry soils 194. 



B. pubescens, in subalpine bush- 

 land 216. 



Birch-forest 334. 



Birches (Betuleta) , in woodland- 

 swamp 191. See also Betula. 



Biennial species, abundant on 

 dune 267. 



Bignoniaceae, as lianes 91. 



Bilateral leaf, as xeromorphic 

 adaptation 194. 



' Black earth,' of steppes 282, 

 283. 



' Black Rocks,' of Angola 241. 



Black-gum swamp, composition 

 191. 



Blekinge (Sweden), develop- 

 ment of vegetation 264. 



Bog-mosses, importance of dew 

 32. See also Sphagnum. 



Bolax glebaria 260. 



Bouteloua, in prairie-flora 28^, 

 286. 



Brackish water, vegetation 1 79. 



Brazil, Caa-Tinga 294 ; palm- 

 forest 347 ; pinheiros 316 ; 

 restinga 229, 272. 



Brazilian, campo, flora 296 ; 

 restinga-forest 229. 



Brigalow-scrub 281. 



Brome meadow, in Alps 289. 



Bromeliacsae, as epiphytes 88. 



Brown, sea-weeds, 'forests' in 

 frigid seas 170; snow 163. 



Bruguiera, in mangrove-vege- 

 tation 235. 



Brunsvigia, infructescence, roll- 

 ed by wind 277. 



Bryophyta, as constituents of 

 hydrocharid-formation 164. 



Bud-scales, in control of trans- 

 piration 115. 



Buellia geograph ica 241. 



Buenos Ayres, flora, Mediterra- 

 nean character 287. 



Buffalo-grass, association 286 ; 

 in prairie-flora 285. 



Bulbous plants, in African tro- 

 pical fell-field 259; in compo- 

 sita-steppe of Cape Colony 2 79 ; 

 in maqui 306; in maqui, of 

 Cape Colony 308, of Chile 

 308 ; in Mediterranean flora 



