638 



INDEX 



Water Avens, see Geum rivale 



— as barrier to dispersal, 105 



— blooms, algal, 29, 480, 481, 483, 



520 

 — , brackish, 472, 492, 502, 508, 523 



— Buttercup, see Ranimciiliis 



— , changes in gas content of, 477, 509 

 chestnut, see Trapa and T. natans 



— conditions, convergence of, 328 



— conservation, epiphytes and, 432, 433 

 ■ — ■ — , plants and, 14, 82, 83, 85, 450-2 



— -cress, see Rorippa tiosturtiiim- 



aqitaticum 



— Crowfoot, see Ranunculus 



■ — currents, benthos and, 498-9, 526 

 — , depth inhabitable by plants, see 



Depth etc. 

 — , dispersal by, 27, 106-1 1, 510, 514 

 — , dystrophic, 318, 476-7 



— economy, 14, 76 



— , erosion by, 568, 569, 570 



— , essential to plants, 76, 301 



■ — , eutrophic, 318-19, 462, 463, 476, 



477, 545 



— -fern, see Marsilea 

 fowl, 112, 114 



— , gas-content of, 477, 509-10 



— Horsetail, see Equisetum fluviatile 



■ — -hyacinth, see Eichhornia crassipes 

 — , light-absorption by, 483, 488, 511- 



• lily, see Nymphaea [13 



family, see Nymphaeaceae 



— loss, cooling by, 87 



— -milfoil, see Myriophyllum 



movement, plankton and, 486, 514 



, plants and, 106-9, 474. 5i3> 525 



■ — , ocean, 507-12, 514 



— , oligotrophic, 318, 462-3, 476-7, 545 



— , periodic variation of temperature in, 



475, 499, 510, 522 

 — , phosphate content of, 475, 476, 524 



— plants (hydrophytes), 86, 87, 93, 484, 



485, 504 



— ■ — , anatomy of, 82, 87, 505 [-13 

 — , penetration of light into, 474-5, 511 



— relations, 47, 51, 54, 82-87, 301-2, 



— requirements, 76 [451 



— retention by grassland, 360, 363, 446 



— Sedge, see Carex aquatilis agg. 

 — , soil, 291, 298, 301-2 



— -starwort, see CoUitriche antarctica 



— storage in plants, 82, 83, 85, 354, 355, 



365, 366, 432, 442-3, 446-7, 450-2 



storage tissue, 82 



■ — , transparency of, 496, 511, 514 



■ — , vertical distribution of plants in, 473 



— , viscosity of, 479 



weed, see Elodea 



Watercourses, plants and, 348, 352, 359, 



361, 365, 374, 439, 440, 444, 454, 



543 



Waterlogged soil, 288, 296, 302, 460, 



559 



Watermelon, 258 



Wattle, 274 



Wave action. Algae and, 495, 513, 525, 



532 



, freshwater lakes and, 406, 492-5 



, shore erosion by, 492, 493, 543, 



Wave-cut benches, 550 [550 



Wax, 3, 266 



Wayfaring Tree, see Viburnum lantana 

 Weakness in competition of cultivated 



plants, 216-18, 564 

 Weathering impeded by vegetation, 555 

 — , soil and, 297, 298, 326-7 

 W^eaver, J. E., 311, 335, 378, 379 

 Weed communities, 374, 375 

 Weeds, 6, 62, 165, 199, 216, 218-19, 248- 



50, 280-1, 309-11, 322, 362, 374, 



577 

 — , control of, 280, 310, 311, 579 



— dependent on human activity, 249, 



250 

 ■ — , derelict areas and, 118 [120, 375 

 — , disappearance of, on abandonment, 

 ■ — , dispersal of, 6, 119-20, 248-52 



— dispersed from America, 249 

 Europe, 249 



— , injurious effect of, 248 



— , open areas and, 120, 165, 375 



— , species almost cosmopolitan, 120, 



249 

 — , tolerance of environment, 219 

 Wegener, A., 165, 169 

 Welch, P. S., 486, 506 

 Wehvitschia mirabilis (Tumboa), 450 

 West Indies, 262, 444 

 Western Eurasia, reed-swamp in, 463 

 Wet and dry bulb hygrometer, 289, 291 

 Wheat, see Triticum vulgar e etc. 



— belt, 564 



— Stem-rust, 248, 251 



— , world production of, 227 



Whisky, 261 



White-beam, see Sorbus aria s.l. 



— Fir, see Abies concolor 



— Oak, see Quercus alba 



— Pine, see Pinus strobus 



Blister-rust, see Cronartiuni ribi- 



cola 



— Potato, see Solanum tuberosum 



— Spruce, see Picea glauca agg. 

 Whitehead, F. H., xviii 

 Whortleberr\', see Vaccinium 

 Widespread occurrence of aquatic 



species, 472 

 Wild Cherry, see Primus avium 



— Oat-grass, see Danthonia 

 Wildfowl, 402 



— , dispersal by, 109 



Wildlife management, 556, 558-9, 577 



