INDEX 



Tensile strength ; tension, 699, 700, 703. 



Terminal bud, 646, 736. 



Termo, 486. 



Testa, 005, 907, 909, 915, 932. 



Tetrad, 830. 



Tetrarch bundles, 683. 



Tetraspore, 811. 



Thallophytes, absorption, 614; conductive 



tissues, 685 ; form variations, 591 (see 



also Algae, Bacteria, Fungi, Lichens). 

 Thallus, 488, 516, 557, 650, 678, 800. 

 Thistle, Russian, leaf section, 630. 

 Thorn, 739, 74*, 754- 

 Thorn climber, 654. 

 Thread, infection, 787, 788. 

 Thuja, leaf variation, 601. 

 Tillandsia, absorptive scales, 615; habit, 



614, 658. 

 Tomentum, 578. 

 Torsion, dehiscence by, QSO. 

 Torus, 680. 

 Toxins, soil, 494. 

 Trachea, 679, 680, 681, 692. 

 Tracheid, 617, 621, 631, 639, 679, 680, 692; 



storage, 536, 631. 

 Transfusion cells, 511. 

 Transpiration, 536, 564, 565, 566; leaf 



form and, 595 ; protection from, 565, 577, 



578, 588. 



Transplanting and root form, 498, 501. 

 Transverse phototropism, 539, 540, 542, 



544, 546. 

 Traumatism, 896. 

 Trees, 645, 648, 649, 650, 709, 710, 717; 



deciduous, 583. 584, 649, 710; evergreen, 



709, 710; leafless, 710, 711; origin, 737; 



rosette, 645; stomata, 560; tropical, 



709; variation, 725. 

 Triarch bundles, 683. 

 Trichome hydathode, 622. 

 Triticum, grain section, 915; root hairs, 



492. 

 Tropaeolum, flower, 843; phototropism, 



540; plastids, 522; pollen, 831; sto- 

 mata, 620. 



Tropical forest, 656, 946; trees, 709. 

 Tsuga, dwarfed, 732. 

 Tube, bacterial, 787, 788; corolla, 859; 



latex, 721; pollen, 826, 830, 832; sieve, 



681, 694. 

 Tuber; tuberization, 671, 674, 675, 720, 



744, 745, 746. 



Tubercle, root, 787, 788, 790. 

 Tumbleweed, 922. 

 Tupelo, 508. 



Turgor pressure, 566, 621. 

 Twiners, 651, 656, 768. 

 Twisting, stem, 543, 647, 648, 673. 

 Tyloses, 559, 695. 



Ulex, variation, 741. 



Ulmus, 655. 



Ulothrix, reproductive organs, 817. 



Umbel, 676, 828, 874, 903. 



Umbelliferae, geitonogamy, 862. 



Underground stem, 667, 668, 669, 670, 671, 



674, 675, 676, 719, 744, 746, 865. 

 Undergrowth, forest, 545, 546, 550. 

 Univore, 765. 

 Uredospore, 764, 813, 814. 

 Urtica, stinging hairs, 577. 

 Use, 948. 

 Usnea, 801. 

 Utricularia, bladders, 618, 619; winter 



buds, 678, 



Vaccinium, stamen, 830. 



Vallisneria, pollination, 837. 



Valves, 814, 920. 



Variation, 486 : air spaces, 553 ; bud, 904 ; 

 chlorenchyma, 533, 534, 535, 538; con- 

 ductive tissues, 686, 689, 690, 692 ; cork, 

 706 ; ecological, 486 ; fortuitous, 950 ; 

 fruit, 916, 917 ; hairs, 573, 574, 575, 576; 

 leaf form, 589, 590, 592, 593, 594, 505, 

 597, 598, 599, 600, 601, 602, 603, 604, 

 605, 606, 607, 608; mechanical tissue, 

 699; parasitic fungi, 765; reproductive 

 organs, 878, 884, 885, 893, 898, 900, 902, 

 903; rhizoids, 516, 518; roots, 505, 506, 

 507, 508, 513; root hairs, 494, 495, 496; 

 saprophytic fungi, 759; seeds, 917, 918; 

 stems, 725, 726, 727, 729, 730, 731, 732, 

 733, 735, 736, 739, 741, 744; stomata, 

 556, 557, 559, 561; taxonomic, 486. 



Variegation, 523. 



Vascular bundles, 530, 531, 533, 534, 53$, 

 581, 617, 621, 680, 682, 683, 684, 686, 

 687, 688, 695, 701, 702, 703; elements, 

 679, 680, 68 1 ; plants, 609, 613 (see also 

 Dicotyls, Ferns, Monocotyls, Pterido- 

 phytes, Seed plants) ; tissue, 513, 551, 

 630, 638, 639, 678, 679, 680, 681, 682, 

 683, 684, 685, 686, 687, 688, 689, 690, 

 692, 693, 769. 



Vaucheria, reproductive variation, 880. 



Vegetative periods, 885, 890; reproduc- 

 tion, 505, 509, 516, 591, 636, 637, 667, 

 668, 669, 670, 671, 672, 673, 674, 675, 

 676, 677, 678, 805, 806, 807, 808, 809. 



Veins, 521, 638, 639. 



Velamen, 511. 



Venation, 638. 



Ventral scale, 516, 517 ; wall, 555, 556, 562. 



Verbascum, hairs, 572. 



Verbena, hairs, 623. 



Vernation, 937. 



Veronica, reproductive variation, 893. 



Vertical leaves, 546, 547, 549, 578. 



