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Full-Text Articles in Life Sciences
Anthocyan Pigments, Paul Sears
Anthocyan Pigments, Paul Sears
Papers in Ecology
Noack has found rhamnose-free flavonol diglucosides to be much more abundant in green leaves than has generally been supposed. In such leaves as he studied he was able to establish the existence of flavonol-anthocyan in couples of similar glucosidal nature, but secured no evidence of aromatic nucleus composition in such cases. He suggests that these couples function as a reduction mechanism during photosynthesis.
Variations In Cytology And Gross Morphology Of Taraxacum Ii. Senescence, Rejuvenescence, And Leaf Variation In Taraxacum, Paul Sears
Papers in Ecology
The variability of Taraxacum has frequently been recorded in botanical literature without receiving much elucidation. It is less often an object of investigation than of conjecture and discussion. A few botanists have studied the effect of environmental factors upon Taraxacum, but their results have not cleared away taxonomic difficulties. Systematic botanists have either looked upon the variations in this genus as fluctuations or slight mutations, and then proceeded to lump or split as judgment might dictate. That life history exerts a profound influence upon form seems generally to have escaped attention.
Variations In Cytolgoy And Gross Morphology Of Taraxacum I. Cytology Of Taraxacum Laevigatum, Paul Sears
Variations In Cytolgoy And Gross Morphology Of Taraxacum I. Cytology Of Taraxacum Laevigatum, Paul Sears
Papers in Ecology
These investigations are the outgrowth of a study, begun in 1914 at the instance of the late Professor C. E. BESSEY, of parthenogenesis in Taraxacum vulgare (Lam.) Schrk. and T. laevigatum ( Willd.) DC. These two species are the common ones in central United States, being respectively designated as Leontodon Taraxacum L. and L. erythrospermum (Andrz.) by BRITTON and BROTVN (3). In 1917 the existence of ameiotic parthenogenesis in both species was confirmed (23) and certain pollen abnormalities briefly described. These abnormalities have invited more critical analysis as a means of throwing light upon certain phases of variation and degeneracy, …