312 



INDEX 



Potamogeton, 126 

 'jx)tassium, 19, 101 

 pot o meters, 64, 67 

 precipitation, 21 

 pressure, 26 



vegetation, 257 

 prevernal aspect, 224 



flowers, 130 

 primary regions, root, 39 



successions, 275 

 principal species, 222 

 production of pollen, 116 

 prolate cells, 172 

 propagation, 113 

 propagules, 112, 113 



of flowering plants, 114 



stems as, 114 

 propulsion, 247 

 Proserpinaca palustris, 167 

 protandrous flowers, 122 

 protection of pollen, 118 



by movement, 120 



seasonal, 121 



structural, 119 

 proteids, 101 

 protogynous flowers, 122 

 protoplasm, selective power of, 48 

 Pseudotsuga, 222 

 Psoralm, 227, 293 

 psychrometer, 27, 28, 29 

 pterospores, 242 

 Pulsatilla, 243 

 pulvinus, 142 

 pyxis, 132 



quadrat, 202 



chart, 204, 205 



competition, 261 



denuded, 204, 209 



list, 204 



major, 204 



making charts, 206 



permanent, 204, 208 



tapes, 204 

 quadrats, kinds of, 203 



marking out, 204 

 Quercus, 184, 292 



novimexicana, 183 



radial zonation, 299 

 rainfall, 21 



gauge, 21 



measurement of, 21 

 Ranunculus, 167, 169 



dtiphinifolius, 153, 167 



sceleratus, 149, 153, 155, 194 

 reactions of plants upon habitat, 282 

 284 



zones due to, 296 

 readings, point and hour, 33 



recessive character, 198 

 records, field, 33 

 reduced bundles, 58 

 reduction of leaf or stem, 146 

 regional classification, 234 

 relative humidity, 25, 27 

 relict method, 287 

 reproduction, 112 



sexual, 115 

 respiration, 101 

 response, functional, 3 



nature of, 3 



structural, 3 



to contact, 141 



to shock, 142 



to water, 7 



to water stimuli, 38 

 resting period ,111 

 results of competition, 258 

 rhizomes, 115 

 Rhus, 292 



rhythm of growth, 110 

 roll form, 162 

 rolling of the leaf, 145 

 root-cap, 40, 41 

 root-hairs, 17, 39, 42, 48 



effect of water content upon, 43 



origin and structure, 42 

 root pressure, 55 



primary regions, 39 



structure, 40 



system, 40 

 root tubercles, 105 

 roots, fonn of, 39 

 root stocks, 115 

 Roripa americana, 153, 167 

 Rosa, 228 

 Rumex, 126, 242 



altissimus, 41 

 runner, 114 

 i-un-oft', 21 

 Ruppia, 125 

 Ruscus, 163 

 rush form, 163 

 Rydbergia, 224 



grandiflora, 223 



saccate fruits, 242 

 Saccharomyces, 105 

 saccospores, 242 

 Sachs, starch method, 83 

 Sagittaria, 167, 169 



latifoUa, 169 

 Saint-Hilaire, on evolution, 188, 192 

 Salix, 126, 220, 242 

 Salvia, 243 

 samara, 132 

 saprophytes, 99, 104 

 sarcospores, 243 

 saxifrage, 88 



