Carnegie Institution of Washington Publication

Carnegie Institution of Washington Publication

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 edition. Excerpt: ...while in cultivated fields the horizontal roots are broken up and distributed, each piece giving rise to a new plant. When this milkweed gets a start in neglected orchards it sometimes forms a solid growth between the trees. Its poisonous nature has been described by Marsh et al. (1920). Asclepias galioides has been much confused with a more easterly species, namely, A. verticillata, a species which is sharply set off by the whorls of numerous fibrous adventitious roots from the lower nodes of the stem and by other characters, as recently emphasized by Eggleston (in Marsh et al., 1920). It is, in reality, much more closely related to A. mexicana, from which it is scarcely distinguishable, except by its usually narrower leaves. Also in the matter of its rubber-content and in its ecologic requirements, A. galioides closely resembles A. mexicana, and it is not unlikely that it should be treated as a geographic variety of this more westerly species. Rubber-content.--The small number of analyses made of this species does not warrant the drawing of definite conclusions as to the amount of rubber present. The somewhat high yield of 5.2 per cent in the leaves of one collection seems to justify the hope, however, that further examinations would show that it would average at least as high as in A. mexicana. These two species are so closely similar in their botanical characters that the extent of variation found in mexicana may be reasonably predicted for galioides. A cross between the two, using the individuals with the highest rubber-content in each case, might bring results of interest. Table 7.--Chemical analyses of Asclepian galioides. ASCLEPIAS BRACHYSTEPHANA. Description.--Plant a comparatively slender leafy herb, 1 to 2 feet high; roots thick more

Product details

  • Paperback | 28 pages
  • 189 x 246 x 2mm | 68g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236574362
  • 9781236574367