804 



INDEX 



Iron, 177, 328; bacteria, 539, 724 

 Irrigation, 236 

 Isoetes, 673 



Jerusalem artichoke and length of day, 



349 

 Joshua tree, 273 

 Juglandaceae, 703 

 Juncaceae, 697 

 Jurassic period, 723 



Kalanchoe leat, 402 



Keewatin center, 734 



Kelps, 631 



Keys to plant species, 24, 83 



Klebs, 337 



Koch, 529; "rules of proof," 573 



Koelreuter, 434 



Kraus and Kraybill, 337 



Kudzu vine, 405 



Labiatae, 714 



Labrador center, 734 



Lactic acid, 156 



Lakes, 590 



Laminaria, 629, 632, 636 



Lammas shoots, 255 



Land habitat, 589 



Lanolin, 215 



Larch, western, 784, 785 



Latex, 172, 282 



Laurentian, 723 



Lavoisier, 108 



Lawes and Gilbert, 531 



Lawn grasses, 40, 43 



Lawns and pastures, 40-48 



Layering, 403, 405 



Leaf, 10, 12, 18-21; arrangement, 21, 23; 

 blade, 18, 246, 248; bud, 68; complete, 

 18; compound, 20, 21; cuttings, 421, 

 422; development, 70, 76; insectivo- 

 rous, 91; keys, 18, 24; margins, 21, 22; 

 mosaics, 81, 216; needle, 19, 682; 

 primordia, 68, 82, 84; prints, 731; 

 scales, 19, 86; scars, 24, 73, 246; sec- 

 tions, 70, 71, 77, 223, 682; sessile. 19; 

 sheath, 18, 86, 271; simple, 21; skele- 

 tonized, 111; spots, 574; surface, 122; 

 tendrils, 18, 86; tissues, 68-75, 71 

 Leaves, form and shape of, 19, 20, 21, 

 22, 85, 90; growing regions of, 76; 



hereditary differences in, 84-94; of 

 cacti, 15, 85; rolling of, 90, 91; uses 

 of, 93; variegated, 132, 435 

 Leeuwenhoek, 525, 526 

 Legume, 363, 366 

 Leguminosae, 708 

 Lemanea, 357 

 Lemma, 357 

 Lemna, 15 



Length of day, 118, 339-344, 349 

 Lenticel, 246, 247, 266 

 Lepidodeudron, 730 

 Leucoplasts, 64 



Lichens, 5, 6, 31, 562, 563, 564, 565, 606 

 Liebig, 527, 531 

 Life cycles, 10, 667 {see also each of the 



plant groups); summary of, 636, 690 

 Light, and abscission, 32; and autumn 

 coloration, 28-32; and bacteria, 517: 

 and bluegrass, 41; and epidermal cells, 

 78; and flower initiation, 339, 342, 

 343; and leaf color, 54; and leaf posi- 

 tion, 80; and leaf size, 53, 54, 77; 

 and leaf tissues, 77, 79; and photo- 

 synthesis, 109, 115, 163, 592; and plant 

 distribution, 165; and plant habitats, 

 589; and stem height, 53, 54; and 

 transpiration, 226, 229; and young 

 trees, 57; effects, 24, 31, 55, 216; 

 energy, 109, 110; in lakes and ponds, 

 590; in oceans, 599; spectrum, 27 

 Lignin, 65, 169, 171 

 Ligule, 19, 76 

 Liliaceae, 699 

 Lily, 700; family, 699 

 Lime, 44 



Linkage, 459, 464 

 Lipase, 139, 175 

 Lipoids, 63 

 Lister, 529 

 Live oak, 508, 789 

 Liverworts. 651-654; leafy, 651, 652; 



thallose, 651, 652 

 Long-day plants, 340, 341, 348 

 Longevity, 396, 679 

 Loranthaceae, 705 

 Lycopodium, 668, 671 

 Lycopods, 668-673, 727 

 Lysine, 144 



