Elementary Studies in Botany |
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Algæ Angiosperms antheridia appear archegonia bacteria beans bearing become body branches Bryophytes called cambium carbohydrates carpels cells cereals common conspicuous corn corolla cotyledons crop cultivated plants developed Dicotyledons disease elongated embryo endosperm epidermis evident example exposed fact Ferns fertilization fiber filament flowers forest fruits Fungi gametes gametophyte garden germination grape green plants green tissue grow growth Gymnosperms hypocotyl illustrations important individuals insects kind of plant layer leaf leaves Liverworts living manufacture means megasporangia megaspore method microspores million bushels moss mycelium nitrogen nodes nucellus obtained oöspores ordinary ovary ovule parasite petals phloem phyte pine pistil plant association plant-breeding potato produced propagation protoplast Pteridophytes regions result roots sacs secured Seed-plants seedling seeds sex-organs showing soil sperms sporangia sporangium spores sporophyte stamens stem stomata strobilus structure supply surface testa tion trees tube tubers usually vascular cylinder vegetative wheat wood xylem
Popular passages
Page 258 - Fig. ii —CELLS FROM ROOT-BARK. A., embryonal stage; B. and C., elongating or growing stages. (Giesenhagen.) arrangement of wood and bast is peculiar to roots. The vascular bundles of the root connect with those of the stem, and these in turn with those of the leaves, so that throughout the whole plant there is a continuous vascular system. CHAPTER III REPRODUCTION STRUCTURES THE root, the stem, and the leaf being the three principal organs in the nutrition of a plant, the matter next of importance...
Page 365 - ... varieties. The need is for good varieties producing small, hard seeds that will not crack and that retain their vitality for more than one year. Many new varieties have been secured from foreign countries and a large number of others developed by hybridization, some of which show great promise. The cowpea is to the South what clover is to the North, and the lessening of the cost of the seed and the improvement of varieties are the two important problems that need to be thoroughly pushed. EXTENSION...
Page 278 - ... beyond their reach. This continual freedom from wave action permitted the growth of more plants, and therefore resulted in the accumulation of more humus, but the soil would still have looked rather bare, as the plants would not cover the surface. The fourth stage was made possible by the accumulation of humus, and it is called the heath stage, for plants of the heath family and their associates covered the ground. At this stage, for the first time, the plants covered the ground so thickly that...
Page 244 - The so-called maple sap obtained from the sugar maple is an interesting illustration of the use of sap that accumulates in a woody stem in the spring. At that time the water has no opportunity to escape through leaf transpiration; so the wood becomes gorged with sap, which can be drawn off by boring into the wood and inserting spiles.
Page 221 - Drosera and grown in swampy regions, the leaves forming small rosettes upon the ground. In one form the blade is round, and the margin is beset by prominent bristle-like hairs, each with a globular gland at its tip. Shorter gland-bearing hairs are scattered also over the inner surface of the blade. All these glands excrete a clear sticky fluid, which hangs to them like dewdrops, and which, not being dissipated by sunlight, has suggested the name of sundew.
Page 220 - The following is a correct description of these plants from text books on botany used in the high schools : "A much larger California pitcher-plant is Darlingtonia, whose leaves are one and a half to three feet high, the hood bearing a gaudily colored 'fish-tail' appendage, the whole structure being a more elaborate insect trap than are the leaves of Sarracenia. In these traps not only are the remains of flies found, but bees, hornets, butterflies, beetles, grasshoppers and even snails have been...
Page 172 - ... wind, and is trundled along the surface like a light wicker ball, the ripe seed vessels dropping their seeds by the way. In case of an obstruction, such as a fence, great masses of these tumbleweeds may be seen lodged against the windward side. This method of dispersal is far more effective than the mechanical discharge; but it is fitful, and its range usually is not very great. Thistle-down may be floated into a neighboring field, and a strong wind may carry the comparatively heavy-winged fruits...
Page 158 - ... pollination. The transfer of pollen from the stamen to the pistil of the same flower is self-pollination, while the transfer to the pistil of another flower is cross-pollination.