Elements of botany and vegetable physiology : including the characters of the natural families of plants / By A. Richard, M.D. Translated from the fourth edition by W. Macgillivray, A.M.

  • Richard, Achille, 1794-1852.
Date:
1831
Catalogue details

Licence: Public Domain Mark

Credit: Elements of botany and vegetable physiology : including the characters of the natural families of plants / By A. Richard, M.D. Translated from the fourth edition by W. Macgillivray, A.M. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    CHAPTER I. OF THE FOOT. The name of Root * is given to that part of a vegetable which, occupying its lower extremity, and most commonly concealed in the earth, always grows in a direction the re- verse of that of the stem; in other words, penetrates per- pendicularly into the ground, while the latter ascends to- ward the sky. A not less remarkable character of the root is, that it never becomes green (at least in its tissue), when it is exposed to the action of air and light, while all the other parts of vegetables, when thus exposed, assume that colour. With the exception of some Tremellre, and certain species of Conferva, which, being immersed in water or vegetating at its surface, absorb the substances intended for their nu- trition by every part of their extent, all vegetables are fur- nished with roots, which serve to fix them in the ground, and to extract from it a portion of the principles by which they are nourished. Roots, as has been said, are in most cases implanted in the ground. But there are plants which, living at the surface of the water, have their roots floating in that fluid, as is observed in certain species of Lemna. Most aquatic plants, as the Buck-bean, Water-lily, and Utricularicef, have roots which, penetrating into the mud, attach them to the soil, and others, which, commonly proceeding from the base of the leaves, are free and floating in the water. * In Latin Radix; in Greek pit,a.. t The filamentous parts, which most botanists have taken for leaves in the Utricularife, are floating roots.