Transpiration, 98, 103. Twiners, 129, 131. Umbel, 159. Undergrowth, 12. Valve, 164. Variation, 2. Vaucheria, 186. Verticellate, 84. Water-pore, 88. Wheat rust, 192. Whiteweed or ox-eye daisy, 155. Whorled, 84. Willow mildew, 190. Wind travelers, 173. Woody fibre, 17. Wounds of plants, 56. Yeast plants, 190. Zygnema, 185. Zygospore, 185, 189. GLOSSARY _accessory_ or _reinforced fruits_ are those in which the ripened pericarp is combined with other parts, as with the torus or the calyx. _adventitious._ Coming by chance or without order, as the sprouts that arise where a limb is cut off. _aggregate fruits_ are those in which several distinct pistils cohere to form one body, as in blackberry, raspberry, mulberry. _akene_ or _achene_. A one-seeded indehiscent fruit, usually small and seed-like. _analogous._ Like to, in function or use. See _homologous_. _anemophilous._ Said of flowers that are pollinated by the wind. _annual._ A plant that naturally does not live more than one year, as garden bean, pea, Indian corn, buckwheat, cowpea. _anther._ The knob or enlargement of the stamen, bearing the pollen. _antheridium._ The male or sperm-cell organ, such as occurs on the prothallus of ferns and similar plants. See _archegonium_. _apetalous._ Without petals. _apical._ At the top. _archegonium._ The female or egg-cell organ on the prothallus of ferns and related plants. See _antheridium_. _assimilation._ The building up of protoplasm from the materials elaborated in the plant. _axil._ The angle or place just above the petiole of a leaf (or pedicel of a flower) where it joins the twig. _berry._ In botany, a fleshy pericarp containing a number of seeds, as current, orange, tomato, grape, cranberry, but not strawberry, blackberry, raspberry, or mulberry. _biennial._ A plant that lives two years. It usually blooms the second year. _blade._ The expanded part of a leaf. _bract._ A small or much-reduced leaf, often a mere scale. _calyx._ The outer row or series in the floral envelope. The outer “leaves” of the flower, usually green. _cambium._ Growth tissue, lying between the bark-part and wood-part of the fibro-vascular bundle and giving rise to the cells of both. _capsule._ A pod consisting of two or more carpels or parts, usually opening naturally. _carbohydrate._ The compounds of the starch and sugar class. _carpel._ One part or member of a compound pistil, or a simple pistil itself. _catkin_ or _ament_. A raceme-like or spike-like flower-cluster that falls away after flowering or fruiting, as of willows and staminate flower-clusters of walnuts and birches. _centrifugal._ From the inside out; as a flower-cluster of which the inside, terminal, or uppermost flowers open first; a determinate cluster.