416 



PLANT SOCIOLOGY 



Douglas fir (see Pseudotsuga) 

 Draba aizoides, 71, 293 



ladina, 187 



siliquosa, 70 

 Dracocephalum austriacum, 114 

 Drepanium filiforme, 16 

 Drought resistance, 127, 132 

 Dry air, influence of, 125 

 Dryas, 185, 269, 317, 319, 330 



drummondii, 318 



-Glohularia cordifolia mats, 18 



odopetala, 71, 152, 155, 156, 318 

 Dryness, physiological, 126 

 Dryopteris, 290 

 Duff, 252 

 Dune control, 153 



formation, 152 



soil, 210, 313 



stabilization, 318, 327, 328 



vegetation, 8, 153, 314, 318, 325, 327, 

 335 

 Dunes, of Lake Michigan, 151, 314, 

 325 



of Sahara, 152 



wandering, 152, 153 

 Dust collector, 114 

 Dysgeogenous rocks, 160 

 Dystrophic waters, 76 



E 



Earthworms, effect on soil, 233 

 Ecesis, 308 

 Echard, 212 



Echinophora spinosa, 153 

 Echium humile, 335 

 Ecologic differentiation, 370 



plant geography, textbook of, 81 

 Ecology of communities, indicators of, 

 64 



schools of, 305 

 Ecotypes, 21, 98, 169 

 Ectodynamomorphic soil, 178, 256 

 Edaphic communities, 371 



factors, 159, 207 

 Edaphon, 367 

 Eichhornia crassipes, 16 

 Elaeagnus, 236 

 Elatine alsinastrum, 99 

 Elementary species, 21 



Eleocharetum, 64 



ovato-atropurpureae, 364 

 Eleocharis alropurpurea, 364 



ovata, 364 

 Elodea canadensis, 16, 178 

 Elutriation of soils, 208 

 Elymus arenarius, 67 



europaeus, 152 

 Elyna myosuroides, 70, 148, 156, 170, 



312 

 Elynetum, 57, 61, 65, 70, 89, 120, 

 121, 150, 155, 156, 171, 172, 176, 

 177, 190, 246, 247, 312, 321, 333, 

 334 



bellardii, 330 

 Empetreto-Vaccinietum, 61, 86, 150, 



263 

 Empetrum, 86, 239 



heath, 132 



-Vaccinium uliginosum heath, 174 

 Encelia farinosa, 138 

 Endemics, 282, 353 

 Endemism, 354 



Endodynamomorphic soils, 256 

 Endohthic algal communities, 188 



communities, 188, 371 

 Endolithophytes, 289 

 Endomyces, 309 

 Endophytes, 289 

 Endozoophytes, 289 

 Endoxylophytes, 289 

 Energy of sunhght, 83, 84 

 Enter omorpha spp., 203 

 Epharmonic adaptations, 297 

 Ephedra, 6 



Ephemeral communities, 371 

 Ephemerum, 289 

 EpiUthic algae, 291 



communities, 188, 371 

 Epilohium, 292 



alpinum, 310 



angustifolium, 239 



montanum, 69 

 Epiphylls, 7 



Epiphyta arboricola, 296 

 Epiphytes, 6, 16 



and exposure, 267 



communities of, 73, 74, 268 



distribution of, 269 



succession of, 309 



