422 



INDEX 



plant life 24, 44, 96, 97 ; geo- 

 graphical significance 33 ; light 

 in, significance 150 ; move- 

 ments, significance 153 ; as 

 oecological factor 28, 29, 44; 

 percolation in soil 46 ; in soil, an 

 oecological factor 44 ; specific 

 gravity, influence on plankton 

 152 ; storage, by land-plants 

 119; temperature, significance 



151- 

 "Water-bladders 121. 



Water-meadows 231. 



Water-plants, see Hydro- 

 phytes. 



Water-reservoirs 119; occur- 

 rence 125. 



Water-tissue 120; internal, 

 occurrence 122; peripheral, 

 occurrence 120. 



Wax, coating leaves of dune- 

 plants 267 ; in halophytes 220; 

 incrustations, as xeromorphic 

 character 193; in regulation of 

 transpiration 103. 



Weapons of species 366. 



Webera nutans, in production of 

 peat in Greenland 205. 



Weingaertneria canescens 212. 



Weingaertneria- association, 

 in Jutland 66. 



Welwitschia jnirabilis, in Dama- 

 raland 276. 



West Africa. See Africa, 

 West. 



West Indies, Calotropis procera 

 in 295 ; Canavalia-association 

 in 227; dry tropical bushland 



301; pasture 327; and West 

 Africa, similarity of mangrove- 

 plants, 237. 

 Wet soil, physiological dryness 



195- 



WTiite, sand-dunes 262, adapta- 

 tions 264, associations and flora 

 264, construction 263; Sea, 

 low-moor 199, sand-dunes 269. 



Wind, drying action 249; in- 

 fluence on form of plant-growth 

 37, on tree-trunks 39, explana- 

 tion of influence 37, 38 ; as 

 factor, in construction of sand- 

 dunes 263, in distribution of 

 vegetation 39, oecological 36 ; 

 mechanical action 37 ; protec- 

 tion against 39 ; utility 40. 



Willow-bushland 32S. 



Willow-region, of bushland, 

 on Norwegian mountains 328. 



Willows (Saliceta), in bush- 

 swamp 190 ; grey, on tundra 

 215. 



Wood-meadow, in Sweden 325, 



335- 

 Woodland, extending into 



desert and steppe 288. 



Woodlands, Mountain-pine 



314- 

 Woody-plants, classes 11. 



X. 



Xanthium spinosum, in vermuth- 

 steppe 278. 



Xanthoria elegans 241. 



X. parietina, on shore-rocks 

 224. 



Xerochasy 277. 



Xeromorphic structure, and 

 soil, ciusal connexion between 

 194. 



Xeromorphy, characters 193. 



Xerophilous plants 36 ; (Thur- 

 mann) 69. 



Xerophytes loi ; among chas- 

 mophytes 244 ; communities 

 134; and epiphytes, similarity in 

 structural features 89 ; ethereal 

 oils 107 ; forms of leaf no; 

 forms of shoot in; growth- 

 forms 127; and halophytes, 

 agreement between 222; pali- 

 sade tissue 107 ; roots 117 ; 

 structural characters 127. 



Xerophytic character of Coni- 

 ferae 310. 



Xylem, reduced in water-plants 

 98. 



Xylopodium 9, 296. 



Y. 



Yucca, in succulent-steppe 279 ; 

 as tropical chasmophyte 245. 

 1'. radios a 271. 



Z. 

 Zamba-pampa 287. 

 Zostera 177, 230; distribution 



178 ; importance 179 ; leaf-form 



182 ; leaf-type 177. 

 Z. fuarma, in production of 



marsh 351. 

 Zosteretum, in aestuarium, 



composition 230. 



