Sentence Examples


  • In the larger veins of the leaf especially in the midrib, in the petiole, and in the young stem, a1 extremely frequent type of mechanical tissue is collenchyma.
  • In the petiole these strands may increase in number by branching, and thotigh usually reducible to the outline of the primitive horseshoe, more or less elaborated, they may in some of the complex polycylic dictyostelic types (Marattiaceae) be arranged in several concentric circles, thus imitating the arrangement of strands formed in the stem.
  • The evolution of the vascular structure of the petiole in the higher ferns is strikingly parallel with that of the stem, except in some few special cases.
  • The bundle-system is of course continuous with that of the petiole and stem.
  • A layer of cork is regularly formed in most Phanerogams across the base of the petiole before leaf fall, so as to cover the wound caused by the separation of the leaf from the stem.

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