. Botany of the living plant. Botany; Plants. 216 BOTANY OF THE LIVING PLANT upwards. There is evidence that the twining is to some tent a geotropic response of a special type. There is here little morphological change beyond an elongation of the internodes, and frequently a delay in the development of the leaves till their support is mred. Such climbers may be dextrorse, following the hands of a watch (Hop), or sinistrorse, showing the reverse, which is more common, as in ( onvolvulus or Phaseohis (Fig. 144). There is here little or no contact stimulus, the twining being a nutatory and geotro
. Botany of the living plant. Botany; Plants. 216 BOTANY OF THE LIVING PLANT upwards. There is evidence that the twining is to some tent a geotropic response of a special type. There is here little morphological change beyond an elongation of the internodes, and frequently a delay in the development of the leaves till their support is mred. Such climbers may be dextrorse, following the hands of a watch (Hop), or sinistrorse, showing the reverse, which is more common, as in ( onvolvulus or Phaseohis (Fig. 144). There is here little or no contact stimulus, the twining being a nutatory and geotropic phenomenon. 1 hit tendrils grasp their support as a consequence of contact-stimulus, which reacts by disturbing the growth while young. The tendril. Fig. 145. Portion of stern of Sicyos, a Cucurbit, with tendril attached to support, x—point of reversal of the coiling of the tendril. See Text. (After Strasburger.) is a cylindrical whip-like organ, usually with a hooked tip. Its sensitiveness is sometimes localised along a definite line. During growth it shows movements of circumnutation : if it then comes in contact with a support, inequality of growth causes the tendril to lap round it. (Fig. 145.) Its morphological origin may be various. In the Garden Pea, Vetch, and Cobaea it obviously represents the distal region of the leaf, including several pinnae ; or it may be the excurrent tip of the lamina, as in Gloriosa ; or extended parts of the lower region of the leaf may be prehensile, while the lamina or pinnae develop normally after the lower region has grasped the support, as in Corydalis, Clematis, and Solanum jasminoides; or lateral ' stipular " structures may be represented by tendrils, as in Smilax ; or again, the tendril may be referable to a whole shoot, as. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the
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Keywords: ., bookcentury1900, bookpublis, booksubjectbotany, booksubjectplants
