INDEX 
Summer-deciduous trees and shrubs, 
71-79 
Sundew, 53%, 54 
Sunflower stem, cross section of, 62*, 
63 
Superior ovary, 132 
Suspensor cells, 303* 
Swamp lands, 321 
Sweet potato, sprouting of, 32* 
Switch plants, 56*, 57 
Sycamore fruits, 168* 
Sycamore log, 111* 
Symbiotic saprophytes, 52 
Symmetry, 129 
Sympetalous, 128 
Synergids, 300, 301* 
Synsepalous, 128 
Syringa (Philadelphus) leaves, ar- 
rangement of, 71* 
Systematic botany, 197 
Taxodium, 26* 
Taxonomy, definition of, 197 
Teleutospores, 254, 255* 
Temperature and germination, 161 
Tendril, 75*, 76* 
Tendril climbers, 74*, 75*, 76* 
Terminal bud, 95* 
Testa, 158* 
Thallophytes, classification of 260,261 
Thallophytes, in relation to evolution 
of plants, 805 
Thickening of stems, 12*, 66, 67 
Thistle, Russian, 167, 168 
Thorn tree, bud section of, 100* 
Thuja, 293*, 294 
Tillandsia. See Spanish moss 
Timber, *107-110 
Timber supply, 112 
Timothy, pistil of, 139* 
Timothy, variation in, 174, 175* 
Tolerant and intolerant trees, 113 
Toxins, 212 
Tracheids, 109 
Transpiration, 22, 28, 79-83 
Transportation of foods, 40, 42, 43 
Tree ferns, 270 
Tree-growing, *114-118 ; 
Trees, 12, 48, 44, 60, 61, 66, 67,78, 79, 
97%, 98*. See also Forestry 
Tube nucleus, 135* 
Tuber, 87*, 88* 
Tubercles on roots, *204-207 
Tuberculosis, 2138-215 
Tumbleweeds, 337*,.339 
Turgidity, 23 
Turgor, 22 
Turpentine, 297 
Twigs, fall of, 77-70 
Twiners, 74*, 75* 
Typhoid, 215, 216 
Underground stems, *86-90 
Unisexual flowers, 127* 
Unit characters, 174 
Uredospores, 254, 255* 
Usnea, 249%, 261 
Ustilago, 252*, 253, 261 
Variation, 173 
Variety, 173 
Vaucheria, *226-228, 260, 264 
Vegetative reproduction, *&7-93, 
220-222 
Vein, 69*, 70* 
Venus’s-flytrap, 54 
Vernation, 271, *273 
Vessel, 64 
Violets, cleistogamous flowers of ,141* 
Virginia creeper, 76* 
Water, absorption of, by roots,9,10,24 
Water, movement of, 37, 42 
Water, pressure of, 24 
Water lily, flower of, 78* 
Water plants, 29*, 78* 
Water plants, leaves of, 78*, 79, 81 
Water pollination, 1389 
Water roots, 29 
Water storage, *80-83 
Water supply, 209, 217 
Water supply and leaf structure, 81, 
82 
Water supply in soils, 321-323 
Weeds, *833-342 
Weeds, injuries caused by, *335-337 
Weeds, origin of, 337 
Weeds, prevention of, 338 
Weeds, success of, 333, 334 
Wheat breeding, *177-181 
Wheat rust, *254-256 
White pine, 283* 
Williams, C. G., 186 
Willow, flowers of, 127* 
Willow, roots of, 29 
Willow cutting, 90* 
Wilting, 9, 23* 
Wind pollination, 139 
Windbreaks, *115-118 
Windstorms, destruction by, 61* 
