INDEX. 



443 



Rattlesnake-weed, 292 



Red algie, 116, 1 19 



Red rust, 129 



Red-snow plant, 118, 119 



Reforestation of lands, 376, 379 



Respiration, 54-58; intramolecu- 

 lar, 58 



Rhabdonia (Rhab-do'ni-a), 117, 

 119 



Rhizoids (Rhi'zoids), 71, 72 



Rhizome, of trillium, 221 



Rhizomorphic (Rhi-zo-mor'phic), 



325 

 Rhizopus nigricans (Rhi'zo-pus 



ni'gri-cans), 120-123 

 Rhododendron nudicaulis, 411 

 Rhodophyceae (Rho-do-phy'ce- 



as), 116, 119, 139 

 Rhoeadineae, 271, 297 

 Rock lichens, 382-3B4 

 Root hairs, 24; absorption by, 19, 



25, 26; acidity of, 27; corrosive 



action of, 27 

 Root pressure, 31, 32, 39, 40 ; 



periodicity of, 32; variation of, 



32 

 Root tubercles, 318 

 Rosa, 276 



Rosaceae, 275, 295, 298 

 Rose (family), 275 

 Rosiflorje, 275, 298 

 Rubiales, 288 

 Rubus odoratus, 275, 276 

 Russian thistle, 268 

 Rusts, 129 



Sac fungi, 136-138 

 Sagittaria, 255 



Sagittaria heterophylla, 402-404 

 Sagittaria variabilis, 400, 404 

 Salicaceae, 262, 294, 296 

 Salsola soda, 268 

 Sand dunes, vegetation of, 376 

 Sanguinaria canadensis, 271 

 Saprolegnia, 123-126 

 Saxifraga virginiensis, 274 

 Saxifragacese, 274, 298 

 Saxifraginse, 274, 298 

 Scorophiilariaceae, 285. 299 

 Seeds, distribution of, 368, 373 

 Selaginella, 193-195, 199-201 

 Sensitive fern, dimorphism of, 



340-346 

 Sensitive plants, 89, 90 



Silkweed, dissemination of seeds, 



372 

 Silphium laciniatum, 88 

 Siphoneae (Si-pho'ne-ae), 109, 118 

 Skunk's cabbage, 356, 357 

 Soil formation, 381-388 

 Solanaceffi, 285, 299 

 Sorus, of ferns 166, 170, 173 

 Spadicifloras, 257, 296 

 Spadix, 257 

 Spartium, scattering of pollen, 



364 



Spathe, 257 



Spathyema foetida, 257 



Spectrum, bands in, 67 ; absorp- 

 tion bands of, 67 



Spermagonia, 132 



Spermatia, 132 



Spermatozoids in gymnosperms, 

 216-219 



Sperm cells, 146 



Sphasrella nivalis (Sphae-rel'la 

 ni-va'lis), 118 



Sphaerotheca (Sphae-ro-the'ca), 

 138 



Sphagnum in moors, 386-394 ; 

 structure of leaves, 394 



Spiderwort, 11 



Spirodela polyrrhiza, 315 



Spirogyra, 2, 93-98 



Sporangium, of ferns, 167-175 



Spores, of riccia, 143 ; of ferns, 

 169-172 ; of equisetum, 188 



Sporidium, 134, 136 



Sporocarp, 112, 113 



Sporogonium (Spor-o-go'ni-um) 

 of riccia 142 ; of marchantia, 

 t49, 150; of foliose liverworts, 

 155-157 ; of mosses, i6r, 162 



Sporophyte (Spor'o-phyte), 143, 

 144, 150, 152, 156, 157, 159, 164, 

 175, 182, 199; of angiosperms, 

 228 ; significance of, 239-246 



Squirrel corn, 271 



Staghorn fern, 345 



Starch, 59; test for, 59, 60; trans- 

 location of, 61; where found, 

 60, 61, 63 



Starch grains, form of, 63 



Staurastrum (Stau-ras'trum), 98 



Sterigma, 134 



Stoma (pi. Stom'a-ta), 38 ; action 

 of, 39 ; demonstration of, 41 



Strobilus, 192 



